Conference 7.286::home_work

Your existing smoke detectors are most likely incompatible with your
security system. The hard wired type of smoke detectors runs on 110v AC,
and I would imagine that third (red) wire is either neutral or 110v.
Typical security systems run off 12V DC, generally with a permanent
charger on a 12v battery so that if you lose power, you still have
security. You may want to wire up an additional 12V smoke/fire/etc
detector to your security system that will work even when the power
is out.

    I've got a wireless system with remote transmitters. As long as
    I can build a switching interface of some sort that will give me
    a nc/no set of contacts, I'll be able to intergrate the systems.
    The alarm has 3 different "channels" for different type of alerts
    which can be interrogated by a central station, so that the proper
    agency can be notified. As soon as I can get some time, perhaps
    a little metering is what's required.
    
    Eric

    Eric

Use the test button and a voltmeter connected to the white and
red wires. See what the output voltage is on the smoke detector
closest to your security system. If the on signal is 115VAC
between the red and the white wires, just add a 115VAC relay and
hook the relay's output to a wireless transmitter.

If the red wire carrys a lower voltage, use a relay of that
voltage rating. Also, it might be cheaper (and more reliable to
get a direct connect detector to your alarm system since it's
battery backed. If you have a electrical system failure, the
battery will still protect you.

cal hoe

    Thanks Cal Hoe, but a smoke detector that is compatable with my
    system are $56 each (they contain a transmitter plus the detector.)and 
    I currently have detectors on all levels of my house that are tied
    together (currently 3, will probably be 4 in the future). I guess
    it will be metering this weekend. I had wanted to delete the ones
    that came with house and use compatable ones with my system, but
    building code required hard wired units!
    
    Eric 

< Note 2470.4 by NSSG::FEINSMITH >
                             -< the saga goes on >-

    I currently have detectors on all levels of my house that are tied
    together (currently 3, will probably be 4 in the future). I guess
    it will be metering this weekend. I had wanted to delete the ones
    that came with house and use compatable ones with my system, but
    building code required hard wired units!
    
    Eric 

What about the suggestion that a simple relay and a remote
transmitter be used with your wireless system. Since the hard
wired system is there and wired to work together, ONE relay and
ONE remote transmitter is all that you need. Si?

cal

       I am in the process of completing an addition to my house. I
    have a new room and an attached garage. One of the things I need
    to do before my electrical inspection is put in some remote fire
    alarms. I have a 110 system that consists of heat sensors in each
    room and a smoke detector above the unit with a battery and 110
    looking wiring. 
    
       I don't trust the original system (appx 15 years old).
     Every so often it goes beeping
    , usally about 3 in the morning. When I took it out of the wall
    the other day, most of the wires had been disconnected.
    
       What I would like to do is install a new unit that can make use
    of the heat detectors  and two additional smoke detectors. I
    went to Somerville lumber, but they do not carry these units. 
    
       Can any tell me where I can pick up schematic or other information
    on how these things work? I am also looking for a place that sells
    these things so I can buy one.
                          
    thanks 
    john

    I don't know if this is the right place to ask, but it seemed the
    closest notesfile. Anyway ...
    
    Last night my smoke dectector emitted several 1-5 second bursts
    for about 30 seconds. Then, silence for the rest of the night. Of
    course, I got out of bed, and checked, and nothing out of the ordinary.
    I couldn't smell a thing.
    
    Background: House was built 5 years ago, and I have a pair of smoke
    detectors wired together (so when one goes off, they both do), and
    they run on 120 VAC. Installed by an electrian. Pretty standard
    for new construction.
    
    The only other time they went off was when the house did fill with
    smoke from the fireplace.
    
    So, any ideas why, seemingly at random, they would go off? If it
    matters, the temperatur in the house was about 79�F, and humid,
    although it has been hotter and more humid in the past.

    Many plug in smoke detectors are photoelectric rather than ionization
    type, although either type could be effected by dirt and dust. The
    photoelectric ones can also be set off by insects taking a walk
    through (don't laugh, I had one that was doing the same thing. When
    I took it apart, I found a spider web inside!). Give the vents around
    the detector a good vacuuming to clean out any accumulated dust.
    
    Eric

    A defective detector can also be the problem. We had three hardwired
    detectors and they kept going off all the time. After swearing and
    smashing the one in the cellar with a shovel I figured one of them
    was not working right. This happened by coincidence when I re-installed
    one of them as the only hardwired detector in the house (the other
    two replaced by battery operated ones).
    
    If cleaning them doesn't work, disconnect them one at a time and
    wait a few days to see if they still go off. When they stop going
    off, the one that is disconnected is the culprit. Replacing it with
    the same brand should be a matter of calling the manufacturer to
    find a source in your area. I don't know if some other brand would
    fit the installation. Does anyone know if the wiring is standard
    on all of them regardless of manufacturer?

<    was not working right. This happened by coincidence when I re-installed
<    one of them as the only hardwired detector in the house (the other
<    two replaced by battery operated ones).
    
	You have just commited a NO NO in Massachusetts which will have to 
	be corrected when you sell your house.  I had the same problem as 
	.1.  The spiders love to make nests in the detector in the basement.  

    What a coincidence!  My system is just like .0 described, except
    it goes off if you open up the bathroom door within 10 minutes of
    taking a shower!  Makes for a great pick-me-up first thing in the
    morning!
    
    Elaine

    
    
    re .4
    
    Same with mine untill I installed a exhaust fan for the bathroom.
    What a difference.
    
    Mike

    
    	Boy I'm glad someone else's detector goes off with steam from
    the bathroom. I couldn't figure out why a *smoke* detector goes
    off with *steam*. Must be some sort of a heat detector also.
    
    John//

>< Note 2497.7 by NSSG::ALFORD "another fine mess...." >
>                     -< cleaning doesn't help this one... >-
>                      .... can I just snip the wires, and put up
>    some other brand?  

      My understanding of NH law is that new construction must have
      hardwired smoke detectors; batery operated ones are no-nos.   This
      may apply to significan remodeling too.  Based on an earlier reply
      I suspect the same holds for MA; and I'd bet that most states
      requre this.   Reason being that many battery operated models have
      batteries removed and never replaced, making them useless.  
      
      However, I see no reason to prevent you changing brands.   If the
      one you replace is connected to [an] other[s] so that they all go
      off together (as NH now requires!)  then you will have to replace
      them all, or at least ensure that the replacement is compatable.
     

    The battery-powered smoke detector I have goes off when the battery
    is weak or when the dried hot peppers hit the hot oil in the wok
    when we have kung pao chicken (of course, most people run out of
    the house when I make that anyhow - some day I will install a chemical
    vent hood that vents to the outdoors over the wok's burner!).  I
    don't have a smoke detector downstairs, although I ought to have
    one there since that is where the woodstove (which we don't use
    since my husband is allergic to smoke) is, as well as other good
    things like the gas furnace, the gas water heater, the solar water
    panels' control and heat-exchanger, and the workshop.
    
    One possible thing that can set off the kind of wired-in smoke
    detectors is anything that causes a burst of current down the line
    that connects them.  The detectors are not usually designed to be
    oblivious to this (although they *should* be! - I get sick of fixing
    up problems like this for my neighbors!  We are ham radio operators.).
    So, the detector might go off if your ham neighbor transmits on
    his radio, or if someone drives by while using a CB radio in their
    car, or if you have a cordless or mobile telephone.  A friend of
    ours spent lots of unpleasant hours getting a neighbor's smoke
    detectors to not sound off in Morse code whenever he used his radio
    equipment.  The design of the detectors wasn't his fault, the
    manufacturer was less than helpful, and the owner of the noisy
    detectors blamed it all on poor Doug (whose own smoke detectors
    didn't have this problem).  The problem was eventually solved by
    installing capacitors across the wiring connecting the detectors,
    and I think the manufacturer ended up doing it.  (Doug ended up moving;
    the neighbor had given him too much grief by this time.)  These
    were brandnew houses, so the smoke detectors were under warranty.
    
    If the detectors do not given false alarms when the wiring is
    disconnected from them, this could be what is happening.  Get the
    manufacturer to solve it so you don't void the warranty.

    Thanks for the replies so far. Neither of them are in an area near
    a bathroom with a shower, so I don't think its steam. Radios? Well,
    this is the first time its happened in 5 years, and I don't think
    my neighbor is up at 2:30 am playing with his CB!
    
    One of them is near the AC blower outlet, so it gets a lot of air.
    That either blows dust into it, or helps blow dust out of it!
    
    Also, I don't know if this is standard or not, but they are wired
    to there own separate circuit breaker. This was _very_ handy once
    when I had to turn them off (house was full of smoke from the
    fireplace), without zapping other random electrical circuits in
    the house.
    
    Maybe I'll at least take off the covers, and clean/dust/remove spider
    webs!

    re .3
    What kind of smoke detectors I use in my house is none of the state's
    business for all I care. I use them and keep them operational for
    my own and my family's peace of mind. The day I get a down payment
    on that house (not anytime in the near future) I will replace all
    of them with something else. Right now it is not done since the
    manufacturer went out of business. Hence the question, can they
    be replaced by another brand without having to rewire?

    
    
    re .9
    
    Most states that I know of say the battery operated ones are no-nos.
    My consern with this is that if you have an electrical fire and
    shorts everything out, your smoke detector won't work. Personally
    I'd rather have a battery operated one, or at least one with a battery
    backup system
    
    my $.02
    
    Mike

    My detector also goes off after a shower as noted in .4
    and will go off if I use my toaster two times in a row (even
    though no smoke can be seen by the human eye)
    
    

    RE battery-operated detectors:

    I just bought a house in Massachusetts.  A smoke-detector certificate
    was required (and presented by the seller) at the closing.  All the
    detectors in the house are battery-operated.  So what gives?

    The law in MA says if you sell a house, you must get it inspected
    by the local fire department, who will issue you a smoke detector
    certificate.  What's typically required for existing homes is a
    smoke detector on each floor.  The rules do not require a hard-
    wired model, only that there be at least one on each floor.
    
    Rooming houses, apartment houses, nursing homes, public buildings,
    new construction, significant alterations to existing structures,
    etc., fall under different rules.  Contact your local fire department,
    which is the final authority as to what is required.
    
    Jim

We used to live in townhouse condos.  We abutted interior stairs and 
bathroom with The neighbor on one side.  There were smoke detectors on 
all three floors, one right outside the bathroom.

One day, they're upstairs detector started going off when they would 
come out of the shower and open the bathroom door.  Of course, this 
meant all three would go off.  They would have to run downstairs 
two floors to the basement and throw the breaker.

So every morning we would hear the detectors go off, and then the wild 
running down the stairs.  They kept saying they wanted to return it, 
but never got around to it.

One morning, he was taking a shower and the phone rang.  He hopped out 
of the shower and answered it in the bedroom.  So he's stark naked, 
dripping wet, talking on the phone.  He looks up and sees a cloud of 
steam heading from the bathroom.  Sure enough, it goes off.  He drops 
the phone, and starts streaking towards the basement.  Next thing we 
hear is crash in the livingroom as he falls over a chair and then a 
string of loud explictives.  He continued hobbling down the stairs, 
favoring the toe and knee he had just smashed, and threw the breaker.

We had a pretty good idea he had fallen over something, but didn't 
know the whole story until he told us later.  I still laugh picturing 
that.  

Anyway, that night they replaced the detector and it has never 
happened again.

RE: vaious
      
      The more-or-less universal code provides that ALL new construction
      must have hardwired smoke detectors, and that they must  be  on  a
      seperate  circuit  with  nothing  else  and  now switch except the
      circuit  breaker.   Battery  operated  units  are  acceptable   as
      retro-fits  in some cases (single family homes,etc.)  but in other
      cases, particularly commercial construction in some areas,  owners
      are  required  to  retro-fit  hard  wired  units.  But I'm NOT the
      authority here; check with your local  building  inspector  and/or
      fire department.
      
      So  far  as  this  not  being  the  state's business, well, it is.
      Building codes are designed to asure that buildings are  safe  and
      don't  present  a  danger  to  the community.  A fire in your home
      endangers your neighbors as well as yourself.  Knowing failure  to
      comply with building codes might also invalidate your insurance.
      
      An aside..
          
          In  the  USA  people  who are burned out of their home tend to
          receive a great deal of sympathy and support from their family
          and  comunity.  I understand that in JAPAN such people receive
          little or  no  sympathy  but  may  be  totaly  ostracized  for
          permitting such a danger to occur!  
      
      The  reason  for  not allowing battery operated units is primarily
      that people remove and don't replace the batteries.   Secondarily,
      batery  units  tyically don't provide a method for setting off ALL
      units if any ONE unit detects smoke. (Obviously this would require
      wiring and if your running wire you might as well run power at the
      same time.)
      
      So far as the imagined danger of having the wiring burn out before
      the detectors go off  --  well,  this  is  possible,  but  if  the
      detectors  are  located according to code it is EXTREMELY unlikely
      that you could have enough fire to kill the power before  you  had
      enough smoke to trigger the detectors. 
      
      Of course this still leaves the danger of a fire starting when the
      power is off -- like from a lightening strike.  That is much  more
      likely,  but  its  also  likely  that the acompanying thunder will
      waken you anyway.  
      
      In the final analysis the dangers of a missing battery are greater
      than those of an  interrupted  electric  supply.   This  fact  not
      withstanding,  I  would think that detectors should be REQUIRED to
      have   built-in,   automatically   recharged    battery    backup.
      Unfortunately it seems that few if any have this.

>      The more-or-less universal code provides that ALL new construction
>      must have hardwired smoke detectors, and that they must  be  on  a
>      seperate  circuit  with  nothing  else  and  now switch except the
>      circuit  breaker.   

What?  Everything I've ever heard suggests that smoke detectors should NEVER
be on a separate circuit.  They should be on a lighting circuit, preferably one 
that is used often.  Reason being that if for any reason the circuit breaker on 
your smoke detector circuit went off, you'd never ever know about it unless 
something that you use every day - like a hallway light - went out at the same 
time.

Paul

    
    	RE: .19
    
    	Your explanation sounds reasonable, but I believe NH *does*
    	require a separate circuit for the smoke alarms as .18 
    	suggests.  I built my house about a year ago and the smoke
    	detectors *had* to be on a separate circuit, and the elec-
    	trical panel had to have in writing next to the breaker:
    
    		SMOKE DETECTOR - LEAVE ON
    
    	This is in Weare, NH.  The building inspector is a member of
    	the fire dept also, so you can imagine the emphasis he put
    	on fire safety.  (didn't look at my plumbing though, hahahaha)
    

.19> ...smoke detectors should ... be on a lighting circuit, preferably one 
.19> that is used often.  

My understanding is that this is now required for new construction in Mass.

The smoke detectors in my last house would turn on and stay on about 
once every 3 years.  Vacuuming them didn't help - I had to disassemble
them and wipe the plate inside that reflects the light.  The things
were thick with dust.  From the angles involved it looked more like
the plate reflected light *away* from the detector, which only would
get light if there was dust or smoke to scatter light.  

	Larry

    RE: .22, thats exactly the way the photoelectric smoke detectors
    work, by having smoke particles deflect the light toward the detector.
    Normally, the light is aimed away from the detector, as you observed.
    
    Eric

    I don't know what time-frame "new" refers to, but my house was built
    new 5 years ago in MA, and the smoke detectors are on a circuit by
    themselves. The electrican was very good, and one who did a lot of
    work for the builders of Deck Houses, so I'm say he knew what to
    do. But, I haven't seen, nor can quote the "code".

    As to labelling of the circuit breaker with the smoke detectors
    on it ... I mapped out my whole house's wiring diagram with the
    standard trial and error method, and I had this one "unused" breaker.
    I never found out what it went to, until the night when the thing
    went off, and I just started at the top of the breaker box flipping
    breakers until it stopped!

My 9 year old house in Londonderry NH has the smoke detector on 
the same circuit as the hall lights. I asked my friend who is an 
about it and he said that's the way they should be wired in NH.

daryll

    I asked two of the questions that were mentioned in previous replies
    to a licensed electrician in Mass. Question #1, Can smoke detectors
    be on a circuit by themselves? The answer is NO. The reason is that
    You may have a tendency to turn them off when doing some work that
    will trigger them off and forget to turn them back on. If put on
    with another circuit,(such as the basement light, like mine is,)
    you will eventually remember to turn it back on.
    
    Question #2, Can smoke detector brands be wired together? The answer
    to that one is NO also. There is no guarranty that different
    manufacturers will work when wired together. I got the same answer
    from the electrical supply house I went to to get 4 new ones because
    I wanted to add one in my new addition and could not find one to
    match my existing ones.
    
    The botom line is this; Would you want to take the chance that they
    will go off if a fire occurred while you were sleeping? 
    
    
    Dave Dufort (who's mind is at rest because he changed his smoke
                 detectors to all the same brand.)

      My  home  in  NH  has  the  smoke  detectors on a seperate circuit
      because the building inspector required me to do it that way. This
      home  was  new construction approximatley 3 years ago.  The reason
      given was to prevent them from being turned of if you had to  turn
      off  anything  else  for  some  reason,  including  an  overloaded
      circuit.  As I stated earlier this circuit  may  not  be  switched
      anywhere except at the circuit breaker.
      
      The  above  sounded  reasonable at the time, and still does, but I
      must admit that the argument for having them on the  same  circuit
      as some frequently used lights is also a good one. In fact some of
      the same arguments as used against battery operated  units  apply.
      If  its  a  seperate circuit and gives trouble, you can turn it of
      and forget it.  Likewise if the dectors go off because of  kitchen
      or fireplace smoke.

      ...then  on the other hand with a shared circuit what do you do if
      the detectors go  off  because  of  kitchen  or  fireplace  smoke?
      (Assuming its night and you NEED those lights?)

    
    My smoke detectors are wired into the house circuitry.  About 1
    and 1/2 years ago, the fuse panel in the basement decided to short
    out.  This caused an immediate power failure in the house, and the
    smoke detectors never made a chirp due to the failure.  Had we not
    been home, or had it occurred during the night, the consequences
    would've been tragic.  I had a fire extinguisher handy which I had
    never used for 3 years,  and was able to put out the fire which
    had already started burning the floor joist, and part of the wall.
    
    More recently ..
    
    Last night I had the alarms go off three times in approx 15 mins.
    Once was just a brief burst, then two more were approx 30-40 seconds.
    This happened at 4:00 Am and was quite unnerving to say the least.
    We searched the entire house for any sign of smoke, and couldn't
    figure out why the alarm went off.  It was an extremely humid and
    foggy morning,  and we had a fan in our window sucking in air from
    outside.  Is it possible that the fog and humidity could have caused
    the alarm to trigger if it's photoelectric ?  How can you tell what
    type of smoke detector it is - ionization or photoelectric ?

    Larry

    Hi, Larry.
    
    My smoke detectors also went off last night in a big way.  In my
    case, I had the whole house fan pulling in the cooler outside air.
     I found no trace of smoke or heat anywhere in the house and I finally
    threw the breaker to shut the alarm off.
    
    There was some fog in the air.  Would that be enough to set off
    the alarm?  Why?
    
    Kevin
    

The ionization detectors that I have seen have a disposal warning on 
them.  If you remove the cover and look either in the cover or on the 
bare material of the detector, you should see numerous cautions, 
instructions for use, certifications etc printed.  If somewhere in there 
it tells you that you must return the unit to the manufacturer for 
disposal, it's probably an ionization detector. (They have a small 
amount of radioactive substance in them, and so the manufacturer can't 
tell you to just toss it in a dumpster, which is undoubtedly what you'll 
do.)

re: .-2

Again, I can only speak for the detectors I've seen, but the new 
hardwired ones seem to all have some sort of battery backup in them to 
protect you when the power goes out.
						>>>==>PStJTT

    My have been blowing off also. As noted in an earlier reply, I removed
    all three and blew them out with a small compressor. I put them
    back together and all was fine for the next two days. Then this
    morning (humid, foggy) they started up again. I have the ionization
    type and I'm ready to ionize them! The breaker is off and so are
    the smoke detectors or should we call them fog/humidity alarms?

    I sympathize with all you folks having smoke detector "false alarms".
    My house is now about 5 yrs. old, and I had trouble with false alarms
    from the first, especially in hot, humid weather.  I tried the
    vacuuming routine with little improvement.  Finally got fed up and
    used a false alarm to isolate the guilty detector.  Pulled it down,
    called the manufacturer to complain.  He muttered something about
    "overly sensitive" units, and sent me a new one free of charge.
    I installed it, and the problem went away FOR GOOD!  No false alarms
    in 3 years!

    Hard wired smoke detectors use three wires, two for 110 v power
    and one for signaling. The signaling wire is the one which
    interconnects them together so if one goes off, all will go off.
    What is the brand detector you have installed? The ones I've seen
    have a connector which plugs in, but some may be spliced with a
    wire nut. As a guess (since I don't know all the color codes), the
    black and white wires are generally for power, while the remaining
    one is the signal. Since they may differ brand to brand, we'd need
    to know what brand yours are to identify the wiring code.
    
    Eric

    HI,
    
    On Monday 10-17-88 I entered another note asking for help, but when
    I got home Monday night and tested the smoke alarm it worked ok.
    Then last night at 12AM and 1AM they went off again. They still
    go off this morning. Can anyone help!
    
    Here is what I know. The unit it totally self contained, I can't
    figure out how to get inside. It mounts to the ceiling on a bracket.
    The base of the unit has 3 holes into which are 3 wires. The wires
    are black, white and red. The red wire is inserted into a hole marked
    "interconnect". On one of the units I was able to pull out, and
    reinsert, the red wire. However, on the other 2 I have been unable
    to pull the wire. The units are installed in my basement, 1 & 2
    floor hallways, and on the roof in the attic. The attic does have
    direct exposure to the outside. 
    
    So far I have tried wiping off the base of the units, to remove
    dust (on all but the attic--I can't get to that one) and blowing
    the hair dryer on it.
    
    One specific question I have is whether there is a way to test,
    assuming I can figure out how to test them, the attic one to see
    if it's the problem one, without having to get up there. You see
    I am afraid of ladders.
    
    Any advice or help would be greatly appreciated.
    
    Thanks,
    
    nancy

I would assume that the attic one is connected via the "interconnect wire"
to the one on the 2nd floor.  Therefore, if you disconnect that wire,
it should isolate the attic alarm from the rest of the system.  If the 
other alarms still go off, then I would say the attic one is not the 
culprit, and vice versa if the attic one goes off, but the others don't.

If you do this one at a time, you should be able to isolate the problem
unit.

One question though... I assume that at least two of the units have more 
than one red wire going into the hole (or a splice in the wire itself.)
Is that a correct assumption.   (should be the ones on the 1st and 2nd
floors)

                           Bob

I had smoke alarms that couldn't be taken apart either.
So I took them apart anyway.  I had to break off one of
the mounting tabs that were supposed to keep the thing
sealed together, but I avoided breaking the other and so
they fit back together well enough.

The earlier note about dust on the black plastic reflector
was exactly the problem I had.  Even with the thing in my
hand, blowing wouldn't dislodge the dust.  Nothing but
firm wiping would do it.  

So if you can find out which one is setting off the alarms,
I would advise you to buy a replacement.  Then go ahead and
see if you can get it open -- if you break it completely,
well, it was already broken & needed replacing anyway.

	Luck,
	Larry

    Success!!
    
    I want to thank everyone for their great assistance. I was able
    to isolate the problem detector. When we got it down we were able
    to locate a spider web inside. I got the spider web out but when
    I tested it it went off again. The next step was to take a very
    strong suctioned vacuum to it. It has worked great ever since.
    
    AFter all this I happended to mention to my neighbor my troubles.
    She said that when one of theirs had gone off she'd gone to M&M
    Hardware (nashua) to replace it. The folks there said that the
    company had discontinued that model as they'd had lots of problems
    with it. They gave her another brand/model which works great. It
    was only $11 and compatible with the othe brand she had.
    
    Thanks again,
    
    nancy

    Now that I have stumbled across people with similar 
    problems, let me tell you my experience:
        
    It was a Thursday evening in late February.  About
    6:30  the family had dropped what it was doing, washed
    up, said grace, and was finally starting to eat supper.
    Conversation with the two boys had started (what did
    you do in school today?), things were generally
    relaxed, when suddenly the smoke detector "right
    over our heads" (about 8 feet away, but it sounded
    like....)  let loose a 3-second scream of alarm.
        
    I just KNEW that it couldn't be from cooking.... we
    have "preventing false alarms" down to a routine by now.
    When we do something in the oven, the wife calls for me
    to remove covers, and slide batteries to "disconnect"
    power before she opens the oven.  (The covers get put
    on the dinner table.... to make SURE we remember to
    reverse the process before eating!)  We hadn't even 
    used the oven tonight....
    
    The relaxed atmosphere was gone... even the two boys
    were sniffing, expecting smoke.  I jumped when the
    alarm went off for another couple of seconds... then
    made a quick circuit of the house - sniffing, checking
    the oil burner (not running), etc. - to see what was
    causing it.  With the rest of the family still ready
    to walk outside, I pulled the cover off the offending
    detector, thinking maybe the battery was loose in the
    clips, or some similar thing was causing a momentary
    loss of power, and the "test" that goes off when you
    plug the battery back in.
    
    What I found was a spider.  Just a small, whitish spider,
    that waved its legs at me... then started to walk.  As it
    did, it walked across the "detector" part of the smoke
    detector.  One of its legs went through a slot in the
    outer metal piece, and touched something inside....
    
    The detector screamed again, the spider ran, and the alarm
    quit.  I started laughing.....  I don't know if the poor
    creature was (electric) shocked, or the sound scared it, but
    boy did it move!!
    
    I explained to the family, and everybody relaxed.  I replaced
    the detector cover, and went back to my meal.  There were no
    further interruptions.....
    
                                  - Ed -        
    

Sort of related...

My detectors are wired into the electrical circuit.  Therefore there are no
batteries to disconnect when it goes off by mistake.  Removing the cover does't
help either and I have to literally unplug the wiring from it.

So say the least, this is a royal pain, especially since when one goes off all
three go off and if you don't unplug the one that started the whole mess it
doesn't help.

Does anybody else have this problem?  

-mark

    re: .40
    
    Yes.  We just throw the circuit breaker.  The only times this has
    happened to us was when we were first learning how to use the wood
    stove, and once from the steam coming out of the bathroom.  Since
    the same circuit controls the bathroom lights, we don't forget to
    turn it back on.
    
       Gary

	RE .40
    		Yes, we have  the  same  problem  but  have a pretty good 
	routine to  unplug  the kitchen detector.  We have a little stool 
	that sits close  by and most of the time just un-twisting the the 
	detector from the mounting  plate  and letting it hang down the 6 
	inches from it's wires will  silence the thing.  If not the wires 
	disconnect with a quick disconnect connector  about as quick as a 
	battery connector.  The biggest problem I  have  is  reconnecting 
	it's hard to line up the slots with  the  prongs  on the mounting 
	plate.

				       ...Dave		
			

I've been having "false alarms" on and off since midwinter.  No smoke,
no unusual smells, but the furnace was always on when it happened.

I finally brought my oil man out to check the furnace, and he discovered
that the chimney was full from the bottom up to where the furnace vent
entered it -- about 4 feet.  So apparently wind was occasionally causing 
a backdraft and pushing fumes out into my basement, where there is a smoke 
dector right next to the furnace.

He shoveled out 1/2 a foot or so of the stuff; now I need to get a
chimney sweep to handle the rest -- I could do it myself, but no way
am I going to!  That stuff smells *awful*.  I suppose an air shredder
would help too, but I don't think it's necessary in this case.

	Enjoy,
	Larry

    re:40
       Yes I had it happen about a month ago in the middle of the day.
    I pulled them all apart and cleaned them. At 1:30 the next morning
    they went off again. I pulled them all and put up a battery one
    for now in a central hallway. I'm considering replacing them all
    with somthing more up to date as the house is 9 years old and the
    hard-wired detectors were put in when the house was built.
    
    bob

    	I've seen times where cooking has set them off (and times where
    my cooking should have set them off :-). If I get enough humidity
    (as in steam) it reacts the same way as smoke in some detectors.

    	The way it was explained to me is that some detectors work by
    looking at the output of a infrared sensor that has an infrared light
    source (LED) shining at it. If something gets in between the LED and 
    the sensor (i.e. smoke, steam) the output of the sensor drops and the 
    alarm goes off.
    
    	Cleaning the LED/sensor should help to reduce the number of
    false alarms but you may also want to consider the location in the
    proximity of the bathroom and oven.	

        Ray

    Actually, the photoelectric type don't have light on the photocell all
    the time. They are looking for light to bounce off the smoke particles
    and hit the photocell only when necessary.
    
    Eric

    After much experimentation, I've finally found the perfect location
    for the smoke detector so it goes off precisely when a 1" steak
    hits medium-rare in the broiler... 
    
    Edd

One warm night last year our neighbor called to see if everything was alright
since they had heard out detector go off. We explained that the grill on our 
Jenn-Air had just finished our steak for dinner... A week later they presented
us with a refrigerator magnet that says:

"If the smoke detector's going off, dinner must be ready"

Bad placement of the 1st floor detector seems the culprit. We all know which
breaker to throw to stop the noise and it always gets reset since my daughters'
bedroom lights are on the same breaker "DAAAADDDDDY! My lights are off!"

    	BTW - A quick way to temporarily stop a nuicense alarm is to
    blow into the sensor.
    
    	Ray 

    I took some sort of hit from the lightning this weekend. The problem
    is my smoke detectors do not turn off. I have electric smoke detectors
    on four levels and I have the to shut the circuit breaker off. The
    only other thing on this line is an outside light that has a photo-cell
    on it. This light does not shut either. Is it possable that a shorted
    photo-cell could turn the smoke detecors on.
    
    Lost my garage door opener also.
    
    	Lloyd

    Contact your homeowner's insurance agency.
    
    pbm
    

    
    This happened to me about 4 years ago, and I had to get all three
    smoke detectors replaced.  In my case, all three got zapped by the
    strike.  
    

    Make sure that the small bulb in the smoke detector is still good.
    If one bulb burns out in my system, all smoke detectors will sound
    until turned off at breaker or the bad bulb replaced. These are
    long life bulbs and should last 5-6 years so make sure you get the
    right replacement. You may have a spare bulb located inside the
    detector housing.
    
    Ray

    Blow in its sensor and it'll follow you anywhere.
    
    In one house I had the kind that connect to the AC and are all wired
    together -- one upstairs, one down, and one in the basement.
    
    First the one upstairs went off every time someone took a shower then
    opened the bathroom door.  Wakes you up better than coffee, I'll tell
    ya.  We had a new detector put in and that problem went away.
    
    Then they started going off at random.  We disconnected one at a time,
    until they stopped going off for a couple of days, and found that the
    one in the basement was the culprit.  When I took the cover off, I
    found lots of rust inside -- no idea how or when it got wet.  Another
    replacement solved that problem.
    

    Smoke detectors are usually wired together, so that if one goes off,
    they all go sound an alarm.  Try disconnecting that wire from each
    detector to see if only one is faulty.

    What brand detectors are these??
    
    Any chance they are made by Edwards Co.????? If so it may just be
    a blown diode if they are low voltage units..

Hi.  I have 3 smoke detectors in my house.  At least I believe that's 
what they are (maybe they're heat detectors).  Anyway, they do not run 
on batteries.  The other night one of them went off in the middle of 
the night with a relatively low volume buzz, as opposed to the loud, 
course buzz it normally makes when you press the test button.  Does it 
need to be replaced?  The other two test fine.  To stop the noise, I 
dropped the plate from the ceiling and disconnected the wire (plug) to 
it.  Any suggestions?

Thanks.

Phil

Phil,

The smoke detectors you mentioned are wired together to trigger
the other alarms to give you the whole house warning. Usually, if
batteries are dying, they chirp at regular intervals. Recommend
replacing them with alkaline batteries.

cal

Cal,

    As I mentioned in base note, these are not batteried powered and 
the "faulty" one didn't chirp, but emitted a constant buzz of less 
amplitude than one normally hears when it fires off.

Phil

    Have you looked at the other notes about smoke detectors.  They
    can be found using the keyword Safety, 1111.86.   Try looking at
    note 2487 with the title _Why smoke detectors go off for no reason?_

    
    phil,
    
    the hard-wired electric detectors normally have batteries for backup
    during power outages.  i believe this is what cal was referring
    to.  try changing the battery, or repositioning the one in there.
    
    if there isn't a battery backup, the detectors may not be up to
    code.
    
    i had to replace two in my house in n.h. for that reason.
    
    ed.

    Enviormental polutients used in the house can raise havic with smoke
    detectors.  I refinished the floors in my house a few years ago.
    and from what I am told the fumes from the poliurethane will cause
    the detection elements to become erratic in their operation. I had
    smoke detectors going off at all hours of the day. 
    
    It sounds like you have hardwired units, and they would be wired
    in parallel, if one goes off they all go off, you might have one
    bad detector in the group. I keep my system in good repair the
    one time you might need it you want it to function properly.

    I don't recall seeing hardwired detectors with battery backup.  I have
    seen ones without backup for sale in both MA and NH, and I'm pretty
    sure that the MA code requires hardwires detectors without requiring
    battery backup.
    
       Gary

re: .5    They appear to be wired in parallel, only one went off and 
when I disconnected it, the others still "tested" fine.

re: .6    I haven't seen any batteries in there.

	I've just built a new Post-n-Beam home and installed interconected
	smoke detectors.  The wood is still very wet and renders the house 
	extremely humid.  The detectors we used are "BRK Electronics"
	Model # 1839WI-12.  The chirp at random and process of elimination
	points the finger at every one.  Just called the company, they are
	aware of a batch of the "Overly sensative  units" and are sending
	out the replacement units, 2-3 week lead time.  It's nice that
	they are replacing them and would have been nicer with better 
	QC on there end.  Now I'll keep my fingers crossed hoping they
	won't be needed.  Better yet I'll pick-up a battery unit or two
	til the replacements arrive.

			BRK Electronics
			Div. of Pittway Corp.
			780 McClure Rd.
			Aurora, Illinois 60504-2495

			Customer Service   (312) 851-7330

   My condo unit has hard-wired detectors. The power is wired in parallel but
there is a control line which runs between both of them. If one goes off then
they both will. If you disconnect one of them then it will have no effect on
the other one. Connect them both, press the test button on one and have someone
check if the other one goes off. Also if it has this feature then it would have
to have 3 or more wires connected to each unit.

   My smoke detectors do not have a battery back-up but I beleieve the company
does offer a central back-up unit. It has been awhile since I looked at the data
sheet.

    Vacuume all (3?) of them. Dust collects in them and can cause false
    alarms. I used to work for an alarm co.( 3 yrs)and pressurized air
    or a light vaccuming cured most "smoke detector false alarms) I believe
    there is a cavity in the detector which has a light source and a 
    light sensor. Sometimes there is also a mirror (light reflects onto 
    mirror to sensor) if the mirror gets dusty the sensor sees a diminished
    amount of light (like it was smokey in the room).
    
                      hope it helps
    
    

    
    Some interesting comments on Smoke Detectors
    
    Most of us have battery operated Smoke Detectors, however I bet
    most of us feel secure because the alarm will cherp when the batteries
    are low or almost dead. Some interesting things I heard is that
    most of us are out alot and when your smoke alarm battery goes dead
    some of them may only "cherp" an hour or two. Of course we then
    come home to think the batteries are fine and could go months before
    we find out its dead. I know there's a national campaign to have
    people check their batteries the same time we turn our clocks forward
    and back during the spring and fall. Interesting thing about alarms
    hard-wired to the home can also fail if the fire starts in the fuse
    box or some other electrical part of the home. The fire could short
    out the whole house and no alarm will sound. They reccomend a battery
    operated back-up. They also gave the percentage of homes that have
    taken the batteries out so they can cook or take a shower and are
    never replaced. I found this article interesting and thought I'd
    share it.
    
    

    I think this is important information and should be reposted because
    of its topic.  I have write locked this but have also reposted it.
    
    The standard write lock note follows...
    
This note has been temporarily write-locked pending approval of the author.

To the author:  This subject is already under discussion in this file, under
the topics listed in the title.  Please look at these notes; you may find that
your question is already answered, or you may find a note where your question
would be an appropriate continuation of the discussion.  Note that since
nearly everyone uses NEXT UNSEEN to read notes, your question will get the
same exposure whether it is a response to a two-year-old note or it is its own
new note. These topics were found using the keyword directory (note 1111), and
you may find other notes relating to this subject by examining the directory
yourself. 

We do, however, welcome new notes if they explore a specific aspect of a
problem that may be under general discussion.  And this moderator has been
known to make mistakes. :^)  So if after examining these notes, you wish to
continue the discussion here, send me mail. 

Bruce [Moderator]

    Reposted by the moderator because of possible implications of topic
    if not noticed.  (Sorry, being a volunteer fireman I have strong
    beliefs in this area.)

            <<< JOET::DUA1:[000000.NOTES$LIBRARY]HOME_WORK.NOTE;1 >>>
                         -< Better living through DIY >-
================================================================================
Note 3552.0                      Smoke Detectors                         1 reply
USEM::SPENCE                                         21 lines  26-OCT-1989 12:40
--------------------------------------------------------------------------------

    
    Some interesting comments on Smoke Detectors
    
    Most of us have battery operated Smoke Detectors, however I bet
    most of us feel secure because the alarm will cherp when the batteries
    are low or almost dead. Some interesting things I heard is that
    most of us are out alot and when your smoke alarm battery goes dead
    some of them may only "cherp" an hour or two. Of course we then
    come home to think the batteries are fine and could go months before
    we find out its dead. I know there's a national campaign to have
    people check their batteries the same time we turn our clocks forward
    and back during the spring and fall. Interesting thing about alarms
    hard-wired to the home can also fail if the fire starts in the fuse
    box or some other electrical part of the home. The fire could short
    out the whole house and no alarm will sound. They reccomend a battery
    operated back-up. They also gave the percentage of homes that have
    taken the batteries out so they can cook or take a shower and are
    never replaced. I found this article interesting and thought I'd
    share it.
    
    

    Since this note has been quiet for awhile...
    
    I'm not sure what is causing the smoke alarms to go off, but it has been 
    very early in the morning, like 1AM or 5:30AM, etc.
    The system is hardwired and has only been giving me the wake-up call
    for about one month.  Only four times.  I have two in the basement
    one on the first and second floors, one in the attic since it has
    stairs to an unfinished unheated space, and one in the attached garage.
    Town code placed them for us.
    
    I know it wasnt' the furnance, the shower, and they have all been
    cleaned.  Could it be that the cold, below freezing is setting the
    attic or garage to go off ?
    The manual says not to use if below 40F.  But I haven't been able to
    find if there are special detectors for outside/below freezing usage.
    
    Any better info will be appreciated.  I dont like having to keep them
    turned off.  I have a new baby and this is very nerve-racking not
    having the smoke detectors operational.
    
    Thanks
    JS
    
    

    Re .53
    
    Our professionally-installed system has smoke detectors only in the
    heated living space in the house.  In the garage, the only suitable
    unit was a temperature detector, since smoke detectors, as you noted,
    don't work below 40F.  Obviously, I don't know if this is related
    to your false alarms, but at least you are now aware that there are
    alternatives for cold environments.
    
    pbm
    

The detector in our unheated addition has never given us problems, even 
though I'm reasonably sure it gets below 40 degrees there.  In the garage,
we were required to put in a temperature detector.  The fire chief, and the 
people responsible for our code, know that putting a smoke detector into
a garage is an invitation to disable the entire system, so they don't even
allow that option.

Do you know which detector is tripping?  Some brands use the indicator light
to distinguish the detector that tripped because of smoke from the ones that
are sounding because they received a signal from a tripped detector.  The next
time they go off on you, look at the lights on all detectors before turning
off the alarm.  The one that's different - perhaps blinking, while the others
are on steady, or perhaps on, while the others are off, or whatever - is the
one that tripped.  Then, if you can't isolate a cause for it to trip, try
replacing it.  

A good electrical supply shop may be of more help than typical hardware or 
building supply stores, which tend to focus on the battery powered detectors.
The electrical supply shop may even be able to locate a detector for you 
designed to work in colder temperatures.

   Gary

    Since it's winter, cold and dry, you don't have a humidifier running in
    your house, do you?
    
    Chris D.

    two step approach.
    First take each one down and using a blower (I've used my shop vac)
    blow out any dust that might be periodically causing a problem.
    If that doesn't work, disconnect one and see if you can isolate the one
    having the problem (unless you can run around and see which one is by
    the lights). Once you've isolated the culprit, replace it.
    		Good luck=========SANFORD========

I had the same problem. I solved it by cleaning.

I was able to locate the one that was tripping by using the light signals. 
The lignt on the one that had tripped stayed on until reset.

My problem was caused by a moth that had wedged itself under the cover and 
died. The dust from his body/wings must have set it off. I vacumned it several
times but it still kept going off. I was about to invest in a new one when
I tried one more thing. I used a can of "Dust Off" (compressed air in a can
sold at photography shops for cleaning cameras and lenses) to blast what must
have been the microscopic dust from the unit. It has been working great
ever since (and I have tested it).

								Mark

    Hopefully someone out there can help me.  I'm having a problem with 
    the smoke detectors in my home.  They go off at all different times 
    of the day and evening for unknown reasons.  They're electric and
    we have one on every floor (basement,main, 2nd floor), when one goes
    off, they all do.
    
    Interestingly this problem only seems to happen during the year when
    we put the heat on, so I tend to think it has something to do with 
    the furnace exhaust.
    
    My husband and I have cleaned the detectors, switched them around,
    and even took the one out of the basement (capped the wires), because
    we thought the furnace exhaust my have been setting them off.  Our
    home is only two years old and we change the filter in the furnace
    often... to avoid any unnecessary exhaust.
    
    Does anyone have any suggestions?  We're considering replacing all
    three, but I don't think the dectectors are defected since the problem
    only seems to occur during the heating season.
    
    Thanks in advance.
    

    For some versions of inter-connected detectors, there is a light
    on the detector (usually an LED somewhere) which will light when
    THAT detector triggers.  You can use this to help determine if
    there is a single POSITION (basement, 1st floor, etc.) which is
    the point of "failure".  (Note that since you've already switched
    detectors one would assume "failure" here means "a location which
    is prone to false triggering".)  There may be air currents or such
    which cause a false trigger.  Then again, maybe you have a VERY
    air-tight house and there is some amount of backdrafting (furnace
    exhaust fumes making their way into the house) which triggers a
    detector.
    
    Is there a chance the detectors are wired onto the same branch
    circuit as the furnace?  There may be an electrical spike caused
    by the furnace motor starting which could falsely trigger the (a)
    detector.  (In our house the attic light is on the detector branch;
    when I turn the attic light on all the detectors "chirp" - kinda
    neat so I can tell if the kids are sneaking up there to play!)
    I believe there is a requirement in either the NEC or local
    variations which requires detectors to be on a circuit which, if
    the breaker tripped, you'd be sure to notice quickly - this is
    often the basement lights, but not always.

Are they on the same electrical circuit as the heater, by any chance? Maybe
noise.

I have the same kind of setup. I had one go bad and start going off at weird
times. Does the brand you have light the indicator when it fires? Mine do.
You can tell which is triggering all the rest - it's light is lit, all the
others still blink.

Anyway, if you can find the bad one, replace just it.

Mickey.

    Thanks for the response so far.
    
    They are not on the same electrical circut as the furnace. They're on
    the same circut as kitchen, dinning room and upstairs hall lights.  
    
    Good point about checking which LED light is lit, and which ones blink.
    I'll watch for that.
    
    Retracing a bit here... I know it's not the basement detector because
    as I said in .0 we took that one out and the alarm still went off....
    I'd like to rule out the vibration/noise because the problem is
    intermittent ... sometimes the detector won't go off for 2 days and
    then out of the blue it'll happen.  So, the vibration of the furnace
    starting would cause it to happen more regularly wouldn't you think?
    
    Interestly, when I walk upstairs to the bedrooms, about 1/2 up I can
    usually feel a slight wind/gush.  So, it's possible that that's what
    setting it off.  The dectector is right at the top of the stairs.   We
    have forced hot air oil heat.
    
    If the dectectors are not defective, I'm still not sure how to solve
    the problem.  We don't want to buy new dectectors, because if it's a
    wind draft, the same situation will continue to happen.  I don't like
    the idea of removing any of them ... for safety reason.  I assume we
    could just reposition the one that is setting off, but then would it
    be inaffective?
    
    This is causing many unnerving nights...  the dectector has been going
    off at 2:00 a.m. - waking up to that is awful ... you don't know if
    there really is a fire or just the alarm.  It's gotten to the point
    where the alarm has gone off so many times that the kids are now
    sleeping through it.  
    
    Since the detector is on the same circut as the kitchen lights, and
    even though I haven't seen any problems there ... is it still possible
    that there's a short in the wiring?  Because now that I think of it,
    occassionally the kitchen doorbell doesn't work and that's on the same
    circut.  Maybe I should just have an electrician check things out. 
    Anyone recommend a reasonable yet good electrian in the southern NH
    area?
    
    Thanks.

    
    
    Are these ionisation smoke detectors?  If so, the problem could be
    caused by particles/fumes that are blown out by the
    furnace.  Sometimes these detectors are "hair trigger" and will be set off
    by airborne particles that you cannot see or smell - even the water
    vapour from a shower or boiling kettle.
    
    Change the furnace filter?
    
    Get the furnace checked for clean burn?  May be some combustion gases
    getting into the circulation side.
    
    Had any other work done such as painting, insulating or
    weatherproofing?
    
 Rgards
    
    C.
    
    
    
    
    
    

    The burner has already been serviced.  Like I said earlier, we removed
    the detector from the basement, so there's no way that the exhaust from
    the furnace could be causing this.... the detector would still have to
    be installed down there for it to go off.
    
    We did recently paint in the house, however this exact same problem
    occured last year at the same time (fall/winter), as soon as we start
    turning the heat on.  The only difference is that this year it's
    happening more frequently.
    
    You're right though...it could be something in the air.  Since we
    have forced hot air, the house can get really dry and I'm sure
    particles of dust move more freely.  We run a humidifier, but have not
    turned the large one on yet.  
    
    Thanks for the input... the more people give their opinions/suggestions
    the closer we come to solving this problem.  I'm going to try and
    troubleshoot the situation with some of the suggestions so far.

    It is not uncommon for hot air furnaces to develop leaks allowing
    combustion gases to leak into the circulated air. I don't know if there
    is a simple way of verifying the integrity of the heat exchanger but I
    would be very suspect of it until proven otherwise. 
    
    You might consider getting a battery operated smoke detector and see if
    it also falses. If so, you almost certainly have a potentially serious
    problem with the furnace.

    I second the notion of checking the heat exchanger for leaks.
    Combustion products can be tricky things and ionization detectors don't
    need billowing clouds a acrid smoke to go off.
    
    One of our hotwired smoke detectors was set off repeatedly by the
    plumber using his torch to sweat some pipes in another room. There was
    no visible smoke, there was no apparent odor, there was no noticeable
    draft.
    
    John H.

The heat exchanger cracked badly on one of my FHA furnaces, and the whole
furnace had to be replaced.  The service man showed be the symptom: the
flame sound changes when the blower comes on, to more of a "roar".  This is
because of the vacuum caused by the air blowing through the heat exchanger
sucks at the flame (that's a technical description).

We've had one family killed and several families hospitalized here in
Colorado Springs in the past two years due to faulty heat exchangers on
furnaces.  If I had the slightest question about my furnace, I'd pop for the
$30 or so to get a professional in to check it.

    I second what .8 said.
    
    	I had the chance to meet a woman who had had the misfortune to be
    poisoned by carbon monoxide *for ten years!*.
    
    	It is a bit of a story, but the short version is that the
    neighboring condo owners vent pipe was (intentionally) blocked by workmen
    who were working on the neighbors unit. The gasses seeped into my
    friends unit and slowly poisoned her. For some reason she got it much
    worse than her neighbor. The sicker she got, the more time she spent at
    home, etc...
    
    	After about ten years of this, the neighbor needed more work done
    on her furnace. As a result the blockage was discovered and corrected.
    
    	My friend is starting to fell much better, but she lost a big
    chunk of her life to being sick.
    
    	The moral? Fire and the gasses they produce are not worth screwing
    up within your home. If your smoke detectors are going off find out
    why. Get your furnace checked out thouroughly. Do the detectors go off
    only during heating season? Will they go off on warm days when the
    windows are open? If you answered "yes" to the first question and "no"
    to the second I'd take a long hard look at the furnace!
    
    
    				regards,
    				Mark

    re.8 &.9
    
    Here in Colorado Springs the Gas Department will inspect your furnace
    free of charge by telling them you think you might have a problem and
    would like to be checked for CO. Call 520-0100. BTW- if they find you
    have a problem they will "red tag" the furnace on the spot I.E. shut it
    down and you will need to have repairs made before it can be relit.
    
    I have called them at midnight-thirty after returning home to a gas
    smell responce was less than 15 minutes.
    
    -j
    

    I am not surprised that they respond so quickly. If they didn't they
    would probably loose customers... *literally*!

    O.k. - I'v eread all 58 replies and I will try to vacuum mine out - but
    I can't get the cover off to clean it.
    
    Tuesday morning my detector went off after I opened the bathroom door -
    since I've been living there since April and this was not the first
    shower I had taken there, I was wondering why now did it decide to go
    off.  Since it wouldn't shut off I just unplugged it.  I tried plugging
    it back in before I left for work but it went off again.  When I got
    home last night I tried plugging it in again but it was still going off
    as soon as I made the connection.
    
    Soooo... I'm sitting here at work holding my CODEONE 2000 smoke alarm 
    and can't seem to pry the cover off.  Did any of you who vacuumed your
    detector do it while it was in one piece?  What else could be casuing
    it to go off?  Its not even close to a burner or a kitchen stove - so
    what else could it be?
    
    Thanks
    Joyce

    	There is probably a good "theory of operation" example in the
    electro_hobby notes file or possibly here even (haven't read all the
    notes), but I'll take a wack it. From what I understand, many detectors 
    work by shining an infra-red light at a sensitive detector. If airborn 
    particles of anything get between the light and the sensor, the sensor 
    gets a lower reading. If the reading gets low enough, it triggers the 
    alarm.
    
    	Over time, dust gets in the sensor area which may partially block
    the sensor and/or the light. This causes the sensor to get a lower 
    reading, but not low enough to trip the alarm. At this point, the sensor 
    is more sensitive to things like steam, which is just airborn particles 
    of water. This is why the shower or cooking may set it off.
    
    	I have never seen one that the cover didn't come off. I have seen 
    some with tight, hard to remove covers. I suspect that's what you have.
    
    	Ray

There are some with non-removable covers.  These have the battery in a
drawer that pops out from the side.  In this case, just run a vacuum over
the grille.

				Steve

    
    
    The steam from the shower sets my smoke detector off, too.  I moved it
    away from the influence of the shower.  I guess steam and smoke look
    similar to my detector. :-)
    

    Well even though I couldn't get the cover off the detector I vacuumed
    it out - thoroughly and plugged it back in...not a peep all night.
    
    I do remember reading somewhere that while vacuuming your rugs you
    should also vacuum behind and under the fridge and the smoke detector -
    now I know why.....
    
    Thanks for all the info
    Joyce

	Well this seems to be the most generic topic on smoke
	detectors so I guess it's as good as any ....

	Does anyone know of a brand of smoke detectors that has
	all these features:

		line voltage
		battery backup
		can be daisy-chained to all go off together
		have a "silencer" button to silence false alarms (in kitchen)

	Home Depot in Nashua carries a brand (FireX I believe) that has
	the first three (3) features, but not the silencer feature.
	And the First Alert brand at Home Depot has one with the silencer
	feature but not all the other features.

	Thanks!

    Try Seaman's electrical supply on Progress Ave in Nashua. It's just
    off exit 5 on the west side of Rt. 3, near the cheap motel right near
    the southbound Rt 3 on-ramp, across from Domino's Pizza. They carry the
    FireX brand, which does show that functionality of the silencer button
    in the info sheets that accompany a new detector, although I'm not
    positive about the battery backup being available on the same units.
    Seeing the battery backup FireX units at Home Depot makes me wonder if
    they do make one with all of those features. 
    
    Mike

> Try Seaman's electrical supply on Progress Ave in Nashua.

	Thanks, good pointer.  Turns out FireX doesn't have a model with
	all the features, but he has a Fyronetics (sp?) brand which does
	and they retail for $14.88.

    
    I received the following notice from BOCA.  I am posting it here
    because of its importance.  Note:  The Firex brand was recalled some
    time ago for other problems but there are still many units being used. 
    Please check any units you currenty are using.
    
    Dan
    
    
    
    Defective alarm prompts recall of battery powered smoke detectors
    
    	Product: Certain models and date codes of battery operated smoke
    		 detectors manufactured by Seatt Corporation sold after
    		 July 10, 1992 by the following firms:
    		      Black and Decker	 Walter Kidde Portable Equipment
    		      Safety First	 Jameson Home Products
    		      Maple Chase	 Funtech
    
    	Problem: The smoke detectors may not sound in the event of a fire.
    
     What to do: If you purchased a smoke detector on or after July 10, 1992,
    		 check the label on the back for the involved models and date
    		 codes.  If you have an affected unit, call
    
    			1-800-952-1331 for Black and Decker units;
    			(or return to Black and Decker service center)
    
    			1-800-492-4949 for all other brands.
    
    -------------------------------------------------------------------------
    
    Six brands of battery powered smoke detectors are being recalled
    because they may not sound an alarm in hte event of a fire.  Today, the
    U.S. Consumer Product Safety Commission (CPSC), in cooperation with
    Seatt Corporation, Downers Grove, Il. urged any consumer who purchased
    a battery powered smoke detector on or after July 10, 1992 to check the
    uniot immediately to see if it is involved in this recall.  According
    to information provided by Seatt Corporation, the brands and models
    affected are listed below.
    
    These battery powered smoke detectors were sold nationwide since July
    10, 1992 in major retail and specialty stores.  Approximately 120,000
    affected smoke detectors are believed to be in use by consumers.
    
    To determine if you have an affected smoke detector, examine the label
    on the back of the smoke detector for the model and date codes listed
    below.  If the smoke detector has been installed remove the smoke
    detector from its brackets by twisting the detector counterclockwise to
    remove the detector from the wall and expose the label.  Only the
    listed models having the listed date codes are involved.  Other date
    codes of these models are NOT involved.
    
    (Smoke detector)
    	FIRM			BRAND			MODEL	DATE CODE
    Black & Decker		Slim Line		SMK100	9228 to 9246
    							SMK200
    							SMK300
    
    Jameson Home Products Inc.	CODE 1 2000		Model A	92192 to 92231
    							Model C
    							Model D
    Walter Kidde Portable	Kidde Smoke		KSA700	92192 to 92231
    Equipment Inc.		and Fire Alarm
    
    Safety First		Baby's room		244	92192 to 92231
    				Smoke and Fire Alarm
    
    Funtech			Safety's First		Model A	92192 to 92231
    
    Maple Chase			Firex			Model A	92192 to 92231
    							Model B
    

    I am in the process of putting an adition on my house, there are three
    rooms over a two car garage. I have 110V wired smoke detectors that I
    can add another to for the living space but I wasted to add a heat
    detector to the garage has anyone ever done this. What I would like to
    happen is that in the event of a fire in the garage the heat detector
    would go off and trigger the smoke detectors to sound. I called the
    mfg. of the smoke detector and they indicated that this would violate
    UL but did not comment whether it was safe. I am getting ready to do
    sheetrock so any help would be great.
    
    
    Thanks
    Tom Casey

    	I don't know why they said it would violate UL. In Marlborough
    	the smokes and heat detectors must all be wired in on the same
    	circuit. 
    
    	Dave

    She indicated that in residential it was a violation but was ok in a
    commercial environment.

    Tom

It will work and is done all the time. (UL problems would depend on the model)

The heat detector (normally open contacts and rated at 120V) gets placed across
the trigger leg from the smoke detector and the neutral leg from the smoke
detector.

One of the other notes also mentioned that in a lot of Mass. towns this is a
required method for protecting the garage. I've also had to do it for attic
spaces and boiler rooms. 


Later


Paul  




	

        My house has 17-year-old Honeywell smoke detectors that are
        beginning to act erratically.  These are AC-powered units
        wired together to sound together.

        The problem I have is that the wiring used to support these
        seems somewhat different from any detectors I've found on the
        market.  My Honeywell detectors are wired  with a 2-wire AC
        circuit plus a twisted pair of low-voltage (thermostat/bell)
        wires.

        The new detectors I've seen require only three wires.  It is
        not clear that the third (signal) wire can be low-voltage
        wiring -- it would seem that the return path is on the power
        neutral line (they are required to be all on the same
        circuit).

        Anyone know if the signal wire can be handled by unprotected
        bell wire?

        Bob

--------------------------------------------------------------------------------
>        The new detectors I've seen require only three wires.  It is
>        not clear that the third (signal) wire can be low-voltage

    I just bought some new detectors to replace my aging/erratic
    detectors as well. The interconnects on these seem to vary from
    manufacturer to manufacturer and even between models by the same
    manufacturer! For example the Firex brand that I got had a list of
    several other Firex brands that it was compatible with BUT
    apparently NOT ALL Firex brands!

    But, the one that I did get, the instructions did list the specs
    of the third signal wire/connection and it was in the low voltage
    range. I got them at Home Depot this summer, I'm sure that they
    still have them

    I'll check one of the saved boxes tonight for the exact model
    number and voltage specs if you're interested.

    Charly

>        Anyone know if the signal wire can be handled by unprotected
>        bell wire?

    I checked the instructions for the new Firex brand smoke dectors
    that I got and YES the interconnect wire can be low voltage bell
    wire.

    Here's the interconnect section of the instructions for the Firex
    brand, Model G Smoke Alarm.

                      INTERCONNECTING SMOKE ALARMS

    IMPORTANT: Only the model G may be interconnected. Model H is a
    singl-station smoke alarm.

    - Use #18 AWG minimum solid or stranded wire. When intercon-
      necting, maximum wire length between any two is 1,500 feet for 
      #18 AWG or 4,000 feet for #14 AWG (20 OHMS loop resistance).

    - Model G smoke alarm may be interconnected with as many as 17
      other Model G smoke alarms. DO NOT connect to any other type
      or model smoke alarm.

    - Connect smoke alarms to a single AC branch circuit. If local codes 
      do not permit, be sure the neutral wire is common to both phases.

        I also called the customer service number for Fyrnetics and
        First Alert, and both of them claim that their interconnect
        wire is low voltage (which makes some sense, since these
        series interconnect with battery backed-up units, which are
        likely to use low voltage signaling).

        Bob

    
    	Does anyone have an opinion about these new smoke detectors
    that are supposed to go 10 yrs. without having to change the 
    battery?  I believe they run off of a lithium(?) battery.
    	Bradlees have them on sale for $10. Seems like a good price
    to me, if they truly work.  You'd hate to find out the hard way!
    
    				Sue

No reason why they shouldn't work.

		Steve

	You can get wired-in detectors that don't rely on
battery power.  Better ones have both - 110 volt line power,
batter backup.  Mine are wired together, too - they all sound
if one goes off.

	Checking your detectors regularly is a good idea anyway,
so I'm not too keen on the install-and-forget-for-10-years idea.
I had line-power only wired-together ones in my house, and a while
ago I got a few false alarms late at night (frightening, but no fire,
and good practice, I guess...).  I probably fixed this by cleaning
them out (bugs and dust), but decided to replace them anyway (nearly
10 years old) and upgrade to the powered models with battery backup.
Even these only cost me $15 each, I think - pretty cheap insurance.
They have a steady green light, signifying 'on' with 110 power, and
a red flash once a minute, signifying battery ok.

	Pick your favorite annual holiday, and declare that to be
replace-the-batteries day - start a tradition!  And rehearse those
escape routes and meeting points!

    I'd like to know if anyone has any ideas to solve what I've run into:
     
     In attempting to change a basement switched ceramic light fixture over
     to a receptacle (for a florescent shop light), it appears that upon
     disconnecting the wiring I set off a house full of smoke detectors.
     I've determined the following:
       1) The circuit breaker which runs the smoke detectors and the basement
          lights was off so the smoke detectors apparently sense for continuity
          in battery backup mode.
       2) The smoke detectors are Firex brand and appear to use 3-wire Romex 
          with the red wire relaying a signal between the detectors and 
          returning on the white.  This 3-wire Romex does not enter the 
          outlet box for the light fixture, and appears to go directly
          from detector to detector.
       3) There are 7 ceramic lights on the basement light switch and
          I've replaced a different one before without setting off the
          smoke detectors.
       4) The detectors are not tied into the switch wiring by accident. 
    
    What I do not understand is given the above, it appears that the
    detector would have to be before the switch in the circuit, effectively
    forming their own continuity loop between the red and white wires,
    so why does interrupting the switch/light fixture portion of the
    circuit send the detectors into alarm?
    
    Any help appreciated.

>>          lights was off so the smoke detectors apparently sense for continuity
>>          in battery backup mode.

The code went back and forth on this - "put them on the same breaker as
lighting so people will know when they are not working" or "isolate them on
their own breaker".  I think its the first way (again) these days.

Your description of their wiring is correct.  14/3 RX is used to:
1- provide power (black/white)
2- provide a common trip (red) (ie one goes off, they all go off)

>>    detector would have to be before the switch in the circuit, effectively

Yes they must be.  Turn the lights off and hit the test button.  My guess is
that they will work.

The Firex brand will usually give off a few chirps when they loose power also
but I take it when you said "they went off" you ment "THEY WENT OFF". 

If you were doing your changes "live" you may have caused a spike in the line
and shorted out one of the smokes.  

Unplug them all, then plug them back in one by one to see if you have a bad 
one.  

bjm