Fireplace sets off smoke alarm with no fire

[DrRod]

Greetings,

My son just moved into a house. The fireplace hasn't been used in years. Today he opens the damper -- builds no fire -- and the smoke alarm upstairs goes off. A bit later he tries again and within a few minutes the smoke alarm goes off again. I can't think of a reason for this. Can anyone give us a clue?

 

[Industrial Toys]

Fly ash? Stuff got stirred up?

I have smoke detectors in a hallway within twenty feet of a smoky fireplace (with cracked heatalator as well) that never go off. Only a foot or so bulkhead separating hall and living room.

Just curious. Are the detectors photo or ionization type?

 

[rustyshakelford]

How old are the detectors? They have a 8-10 max life span. If 8, I'd replace them. Takes about 2 mins each and that's a new pig tail and base too. If they are still good, get a can of compressed air and blow them out. They accumulate dust and stuff that causes false alarms. Make sure the batteries are new. 9v is the standard. If it's a wired system they say every 6 months, if no times of extended power outage, you can go to 12 (my opinion).

Opening the damper without building a fire could of stirred up some fine ash to spread thru the house. It causing a detector to go off upstairs is unusual. Could just be a coincidence. Also, it could've been a detector in the fire place room that activated and it set all of them off.

Brett

 

[Ford850]

Cold chimney is down drafting, and the house is sucking in dirty air from there. If he has any bath, kitchen, or water heater exhaust fans running that encourages the down draft even more.

 

[dmccarty]

The alarms could also go off if there is high humidity.

Later,
Dan

 

[ThirdMan]

Cold chimney is down drafting, and the house is sucking in dirty air from there. If he has any bath, kitchen, or water heater exhaust fans running that encourages the down draft even more.

Could it be the opposite? Could the chimney be pulling air out and the water heater could be exhausting into the house?

 

[oosik]

Want weird - my TV remote control can set of my smoke alarm.

 

[4570Man]

Could it be the opposite? Could the chimney be pulling air out and the water heater could be exhausting into the house?

I doubt it. I can't open the stove doors at the same time my kitchen stove vent is running or it sucks in smoke.

 

[Industrial Toys]

I had a customer call me all irritated. Smoke detectors wouldn't shut off. Several phone calls later and he was still more irritated. Finally I had him power down the security system and disconnect the back up battery. The noise persisted.

He (A Doctor) called back a while later to explain that he found a childs toy in a toy box making all the noise. I don't think any apology was ever offered.

 

[Slowpoke Slim]

Op,

The detector itself is probably filthy inside, and the sudden air movement is stirring dust up from inside the detector. I would recommend your son just replace them all to start with, since he just moved in. Just the humble opinion of a NICET certified fire alarm tech (commercial systems).