Went off at 5.00am this morning! I nearly had a heart attack! Woke the missus up and investigated and absolutely nothing going on. Theyre all going off as theyre mains powered and connected together - only lasted about 30 seconds then stopped. It then did it about another 3 times over the next 10 minutes so I turned the smoke alarm circuit off (before the neighbours came round). Will turn it back on when I get home tonight and see if its still doing it. Cant think whats caused it though - dust maybe?


The cats looked well angry!

Mine did this the other week, except it would only beep a few times then stop, but started doing it randomly for a few hours from about 5am.

In the end I got thoroughly peed off with it and wrenched it off the ceiling. When I put it back it stopped again!

I never did figure what caused it.

And WTF is with them putting in the square batteries which are clearly user replaceable, then sealing over the housing with plastic to stop you swapping the batteries?


[ Sorry that was Nige posting! ]

Its nearly a weekly occurrence with my dad cursing at the smoke alarm just outside the kitchen when hes cooking. One time he was pissed off enough with it to hit it and send it flying. If it annoys him so much just fecking move it further down the hallway, or stop cooking with the kitchen door open ><

Replace the buggers.

I heard they work on air density or something, so dust or mist/fog can set them off ?   (tho maybe thats not all of them?)

change the Backup batteries in them, normally a 9v PP3

Quote from: knightyI heard they work on air density or something, so dust or mist/fog can set them off ?   (tho maybe thats not all of them?)

They also contain radioactive materials

I thought the ionised air from the smoke creates a current between the 2 terminals in the "hole" ?

QuoteIonization smoke detectors use an ionization chamber and a source of ionizing radiation to detect smoke. This type of smoke detector is more common because it is inexpensive and better at detecting the smaller amounts of smoke produced by flaming fires.
Inside an ionization detector is a small amount (perhaps 1/5000th of a gram) of americium-241. The radioactive element americium has a half-life of 432 years, and is a good source of alpha particles.

http://home.howstuffworks.com/home-improvement/household-safety/fire/smoke2.htm

Quote from: EddI thought the ionised air from the smoke creates a current between the 2 terminals in the "hole" ?

I think the isotope emits alpha particles into the air between the terminals and this creates a current, and when the smoke obscures the alpha particles the current drops and the alarm sounds.

But I could be woefully wrong.

Edit : Zpyder beat me to it.

Ah well sorta on the right track I guess. All I know is theyre a right bugger when youre trying to make cheese on toast. Have to take the bloody battery out everytime

thats all lies, everyone in the know.... knows smoke alarms are full of spiders trained to smell smoke

the problem is, spiders dont live that long, so they have to reproduce and pass there training onto there young.... inevitably a few things are lost along the way.... such as telling the difference between "OMG MY HOUSE IS ON FIRE" and "cheese on toast"

Im reasonably sure the items fitted to my house are actually "your food is nearly done" alarms.

On the plus side, if my house ever does catch fire they should let me know quick-smart.