110V Smoke mystery

[Oakey]

I try not to bug you guys but I'm stumped with this. The house has 9 BRK smokes and 2 CO/Smoke combos interconnected 110V with battery backup. In the middle of the night it seems they go into alarm for about 3 seconds, when the homeowner kills the 110V and they run on battery they are fine .
I thought maybe a power company switchover in the middle of the night but nothing else shows signs of that, time clocks etc. The detectors are about 6 years old... I also vacuumed them and tested everything seems right. I replaced the CO/Smoke combo on a hunch but it didn't do anything to fix it.
I hesitate to replace them all just to have this issue reoccur. Any suggestions would be helpful

Thanks

 

[LarryFine]

Disconnect one, 120v and battery. If it happens again, reconnect that one and disconnect another.

Another possibility is that one is detecting something, and responding properly.

 

[S'mise]

I had the same thing happen, The "Larry" method works great to pinpoint the alarm source. If it was me I'd just replace them all. I believe the life of somkes is only about 7 years anyway. A tiny bit of dust is probably triping one of them.

 

[MichaelGP3]

Had your boiler/furnace checked out lately?

Had your boiler/furnace checked out lately?

I don't know that this is your problem, but if it was me, I would have a pro come in to take carbon monoxide readings. You're thinking that this is an annoyance; it's safer to bet that it's not.

 

[hurk27]

BRK's will tell you which one set the alarm, look for the one with a slow blinking red light, then find out why or replace it, it could be to close to a heat vent?

Smoke detectors test for two things, obviously smoke particles, but also they monitor for fast rise time of temperature, the latter is why its not good to install them in kitchens or attics or other places with a heat source.

 

[kbsparky]

...A tiny bit of dust is probably triping one of them.

We had spiders putting webs into smokes tripping `em out. Hard to get that out with a vacuum as well ....

 

[gary]

I also vacuumed them and tested everything seems right. I replaced the CO/Smoke combo on a hunch but it didn't do anything to fix it.
I hesitate to replace them all just to have this issue reoccur. Any suggestions would be helpful

Thanks

Did you install fresh batteries in all the units? I've had problems with BRK's that had weak batteries. This caused false alarms in the middle of the night when falling ceiling temperatures would push them over the edge. The battery voltage was low enough to cause false alarms but not so low as to trigger the low battery chirp alarms.

 

[ptonsparky]

We had 1 of 13 fail in a new home the first weekend it was occupied. All 13 went off as planned twice that night. Their 9 yr?? old slept thru it even with one 10' away in the same room.

Spiders and dust webs are a real pia. We usually replace them.

 

[G._S._Ohm]

when the homeowner kills the 110V and they run on battery they are fine .

A battery is guaranteed smooth DC but 110vac rectified and filtered may not be if the filter capacitor has failed to a lower value.

 

[Oakey]

Thank you guys for all the ideas on this issue, I never would have known most of them. I'm going there next week and Ill utilize all the troubleshooting points here. I know replacing them is simple but I'd like to try and pinpoint it so I can be sure, this customer will pay thankfully

 

[tmason]

take into cosideration that the detectors recomended life is 7 years no more then 10 if they are 6 years old it would be more profitible to replace them all know and cost effective. also i use kidde they are great. best of luck just wanted to throw that out their no ones life is worth being cheap thats my modo again good luck.

 

[dhalleron]

We had 1 of 13 fail in a new home the first weekend it was occupied. All 13 went off as planned twice that night. Their 9 yr?? old slept thru it even with one 10' away in the same room.

Spiders and dust webs are a real pia. We usually replace them.

Per fire alarm code and the manufacture's instructions there are supposed to be no more than 12 smoke alarms interconnected. Up to a total of 6 other devices such as CO alarms can be installed not to exceed 18 devices.

 

[dhalleron]

New smoke alarms have an expiration date on them. Per fire alarm code residential smoke alarms need to be replaced every 10 years. CO alarms have a life of 5 to 7 years depending on the brand.

My personal home smoke alarms went into alarm one night about 3:00 AM. They were one year past the expiration date so I replaced them all.

 

[Oakey]

Well after some time has gone by since I was there to repair the smokes I can finally say the culprit was dust, and a lot of it. Some compressed air and we have success, thank you for all your replies!

 

[jaylectricity]

Had a customer with this problem. Turned out the conductor was not actually terminated under the screw of the circuit breaker. It was just resting there, held by various forces of wire tension and gravity. Every once in awhile, heat or vibration or the lack thereof caused by dawn or dusk would cause the conductor to lose connection with the breaker. When the connection closed again the detectors would immediately go into "TEST" mode and alarm.

This happened several times over the course of a year and wore the batteries down which only compounded the problem.