our smoke/fire detectors went off in the middle of the night--the one downstairs first, then the one upstairs, with no detectable cause. We opened some windows and the shrieking stopped. What could have caused this?

This morning as we sat at the breakfast table, a bright light flashed above our heads. The light over the table was off, and it didn't come from the other kitchen light. It last only a second. What is going on?

RickJ

So did you not smell anything at all when you got up and opened the windows?

The bright light is indeed a mystery but almost certainly not related to the smoke detectors.

Are these smoke detectors hard wired? If so,
1. it's typical that when one goes off so do the others that are hard wired, and
2. one going off for no reason is frequently a sign that it's time to chuck it and plug in a new one.

weezercat

Yes, they are hardwired, I believe, as you plug wires from the detector into a panel in the ceiling. They also have 9-volt batteries.

We smelled nothing when we opened the windows, and the detectors went silent when the windows were opened.

My husband is an alarmist and suspects foul play, which I think is ridiculous.

???

RickJ

Ok: the first one that went off is probably going bad. Take that one to the store for a replacement (look closely at the plug type to be sure you're getting one that will not require rewiring). If you find the same make and model, fine. Get just one. If you can't find the exact make and model, get 2 of them and replace both.

Fr_Chuck

Of course they will go off if and when the battiers get low. And if they are on a hard wired security system, the styem does tests of the system normally at night. ( normal settings on equipment) So if the 9vt were both put in on the same day, it is possible they are both getting low at the same rate. ( not really likely to both go to the low level on the same day but possible)

And of course with any systems, they do require regular maintance, cleaning and also checks by the monitoring company is always helpful.

I have a wired system, that is monitered, I had a yard full of fire trucks last month when I decided to bug bomb the house and forgot to turn off the fire zone alarms in our home.

captain tony

I agree. Our smoke detectors are hard wired and battery powered however they beep for a long while - days - to alert us that the 9 volts are getting low. I have always replaced them before they ran completely down so I don't know if they would trigger an alarm.

Twice now over six years our detectors have gone off for no reason in the middle of the night and scared the begeezeus out of me and my family. Tomorrow (with the suggestion of the forum) I will clean out all of the detectors and replace batteries - see if that helps. If it happens again I will go on out and purchase a whole new set of detectors. (The alarm ran only for about 30 sec. - maybe less - before stopping.)

ballengerb1

Tony, this is an old post but your comments are still valid. If you get to that point of removing the old alarms you can temporaily hardwire them one at a time to find the bad one. You can them just replace whats broken.

captain tony

Thanks - great idea :-)

Stratmando

To add to Ballengers, temporily capping interconnect wire will help locate offending detector.
One company that starts with a "B" had problems with their detectors, they knew by the date, but I uncovered another batch and they replace all from the factory.

sbowman1030

I've been in the security business for over 16 years. My suggestion is to buy a can of compressed air, like the one you use for your keyboard and spray the detectors. Too often the get filled with dust that will cause the detectors to go off.