Mains powered smoke detectors going off randomly

grahamor

Hi,

We moved into a new home 2 weeks ago and there are 2 mains powered smoke detectors. They started going off randomly as soon as we were moving our belongings into the house.

The only way to shut them off is by cutting their power at the fuse board. There is a dedicate fuse for the detectors.

Last night they went off at 2am when all the lights were off. The previous night it was 5 times in a row. They seem to be painted over so not easy to open.

Could it be dust or maybe an electrics problem ? Could there be a backup battery inside that's worn out ?

I'm thinking of just replacing them with battery powered ones.

Any advise/tips appreciated.

KoolKid

Probably need changing. If it were the battery you would be getting the chirp every 40-50 seconds.

DublinDilbert

Are they the same manufacturer?

I've seen problems where ones from different manufacturers were linked

JonathonS

Sounds like dust. Some of them are incredibly sensitive.

delly

They are most likely at the end of their life. I had the same issue a couple of years back, and it specifically happened on colder nights. See below info from another site, but replacement is the only way to go.

1. Check batteries. Voltage drops with temperature.
2. Check age on smoke detectors(as they get older they ionize less
and less, so the sensing chamber drops faster with any type of
dust/smoke/humidity). NFPA recommends replace every 10 years, but I
was told replace at end of warranty period(some 5 years) under harsh
conditions, since the company only guarantees it's function in the
warranty period.
3. Check for improper installation, if they are in colder rooms the
air gets denser than the smoke detectors were 'designed' for. Meaning
air at normal room temperature(68-75F) is less dense than air at 40F.
Dense air can appear like less-dense air with smoke in it. So this
creates for a false alarms.

When I replaced mine, it was a case of leaving the original electrical mount on the roof, then just slipping on the new unit. If you look at the below link, you may recognise your model. They should be able to be picked up in any decent electrical wholesaler.

http://www.eielectronics.com/product-selector/80-product-list/186-mains-powered-hard-wired-alarms.html

Stoner

You wouldn't really want to just change them to battery units, that's a step backwards advice above is good