smoke alarm

[TimWafer]

3 nights ago the smoke alarm in the bedroom went off at 3 AM. Not just a low battery beeping but also a full alarm where I had to remove the batteries. Not a pleasant thing to wake up to. Checked all through the house and all seemed well. Figuring the smoke alarm was 20 years old; maybe it was bad and replaced it with a brand new one the next day. All went well that night but then last night the new one went off!! Now I’m really concerned. There are 4 other smoke alarms in the house and all check OK with the test but none have gone off for any other reason. Yet 2 different smoke alarms have gone off in the bedroom on two separate nights. I can’t smell or see any smoke anywhere. I even disassembled switches & receptacles in the room in case there was something arcing in a connection somewhere. All seemed fine there too. I’m going to check around some more when I get home tonight but am pretty well stumped.
Only other thought that comes to mind is it has been abnormally high humidity the last few days. I know I once had one give me trouble when it was located right above a humidifier. Not sure how much humidity it takes to set one off but then again why don’t any of the others go off.
Anybody have any ideas.
Tim

 

[Janicholson]

Most of them use a tiny bit of radioactive material (americium) to ionize air across a gap (internal to the works of the device. Anything that will block alpha particles (a very weak radioactive decay particle that will not go through a piece of paper) will reduce the flow of electrons across this gap. This includes water vapor (at fog levels) dust, dirt, and paint particles. Smoke particles are very good at this blocking action as well. I would do as you have been, making sure there is no smoldering potential fire of any kind. I would suggest two changes. One is to light a match and blow it out then drift the smoke into the bottom of all the detectors you have to be sure they work on smoke (they will, they are pretty reliable) then I would place the one in your room in a different location (probably over the door to the rest of the house) and see if that madkes a difference. I hope this helps, JimN

 

[Bus Driver]

Tiny insects can trigger the alarms, spiders too. Dust will do it. Since they are new, dust should not yet be in them.

 

[Anonymous-0]

You think that is bad, I just built a house and we have to wire all the detectors to one another. Twice in the year and a half since we have been in the house they ALL have gone off for no reason. It really is a scary thing when they go at 3 am! Running around lookin for smoke and double checking everything really makes you worry.

 

[RP3]

Could this be due to condensation in the unit? Has anything changed like the temperature/humidity of the room?

Have you been running the air conditioner all day and then opened the window at night letting moist air in, etc., etc...

 

[Pappy]

Our smoke alarms are wired together and I had a false alarm a week ago. House is 20 years old. I could find no problem, so I dusted the alarms with a fine brush and all aroud them and no more problem. Could have been the dust, or cobwebs clinging to the blown in ceiling texture.

 

[Anonymous-0]

It's 3:00 AM here in Los Angeles.. Alarm went off briefly around midnight, and then again (longer, but less than a few seconds) now. Woke me up and scared the hell out of me. Opened up the fire alarm and a spider (larger) crawled right out (needless to say, again I was startled out of my mind). I don't know if this is it--they say you need to sweep out dust from these things...but if dust can do it, I'm guessing this ugly little guy could easily be to blame.