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dolphinsndogs · Sep 30, 2009, 07:50 AM

I have 4 smoke alarms in my home; they are all hard-wired. I have had to disconnect completely--take them out of the ceiling--two of them as they went off for no reason. I took the 9 volt battery out of either of them first. That didn't stop it. Then I pulled the alarm out of the ceiling and 'unhooked' the alarm from the plastic 'thingy' which is connected to the black, white and yellow wires. One of the alarms stopped beeping but the other one continues to beep just once in 5 to 8 minute intervals. HELP! (Please) I and my dog are going crazy and I can't go to work till this is fixed. Thanks!

WallyHelps · Sep 30, 2009, 10:57 AM

If you haven't noticed it by now, I would assume that it did eventually stop beeping. With the power disconnected and battery out, the only source of power for the beep would be a charged up capacitor inside the detector. I've also tried pressing the "test" button in an attempt to discharge the capacitor more quickly--although I have no proof that this actually helps.

Anyway, I hope it has stopped on its own.
WallyH

KISS · Sep 30, 2009, 11:34 AM

Not knowing the exact model of the detectors, I'll give his account:

The batteries are for backup only.
The detectors most likely have a continuity function built in, By taking one out of the circuit, you mayhave disturbed the baility to detect a fault. The beeping, may in fact, mean that a detector senses something wrong with the wiring.

Smoke detectors are either photoelectric or ionization. Photoelectric detecors are VERY sensitive to dust and must be cleaned with a can of spray air.

Ionization detecors are a bit more expensive and contain a bit of radioactive material. Those are capable of putting an electrical charge on the smoke and a small amount of dust won't set them off.

Clean them with a can of canned air. CHeck a full-service camera store. http://officediscountclub.com/air-cans.aspx

KISS · Sep 30, 2009, 01:40 PM

I did forget to mention that the smoke detectors should be on a separate circuit, so removing batteries and AC power should stop them from beeping.

Missouri Bound · Sep 30, 2009, 05:31 PM

If your detectors are hardwired, they most likely will all beep if only one is affected. Removing all the batteries and disconnecting the AC will stop the beeping. And that interval you talk about is probably one with a battery still in it, and the battery is low, which causes the unit to beep as a low battery warning.

WallyHelps · Sep 30, 2009, 05:50 PM

Originally Posted by KeepItSimpleStupid

The detectors most likely have a continuity function built in, By taking one out of the circuit, you may have disturbed the baility to detect a fault. The beeping, may in fact, mean that a detector senses something wrong with the wiring.

I was assuming that the beeping unit was already disconnected, but a re-read of the problem is inconclusive. With no battery and no AC power, it should stop beeping on its own.

WallyH

KISS · Sep 30, 2009, 06:10 PM

Wally:

Re-reading the OP's post is also inconclusive except that the 8 minute interval was likely due to low battery or no battery.

I pulled up this this info from the web from aleading mfr: Kidde Smoke Detector Alarm PE120E

And the instruction manual uses beeping and LED indicators to figure out which detector is the cause of the problem.

I was misled by the term "going off" to mean in alarm condition.

A removed battery should also be detected as a low battery.

It's unclear whether all the detectors would be beeping at a long interval in a low battery condition. I suspect the answer is yes.

It also did not address what happens when they don't have AC power.

WallyHelps · Oct 1, 2009, 04:48 AM

Originally Posted by KeepItSimpleStupid

Wally:

Re-reading the OP's post is also inconclusive except that the 8 minute interval was likely due to low battery or no battery.

<snip>

A removed battery should also be detected as a low battery.

It's unclear whether or not all the detectors would be beeping at a long interval in a low battery condition. I suspect the answer is yes.

It also did not address what happens when they don't have AC power.

Hi K.I.S.S. -
I think we're on the same page here. The point I was trying to make was a smoke detector that is disconnected from AC and has the battery removed would have no source of power to make a beep (except for possibly a charged capacitor--which should discharge fairly rapidly).

At least that has been my (somewhat limited) experience with these things.
WallyH

ZoeMarie · Oct 1, 2009, 04:55 AM

To add to what others have said, I have a fairly new kidde smoke alarm. I don't know the model off hand, but I took it down to paint, so it was disconnected. It was beeping every few minutes or so and because I didn't have a new battery to put in, I pulled it out thinking it would stop the beeping. It continued to beep for days until I put the new batteries in.

ZoeMarie · Oct 1, 2009, 04:57 AM

Also, on the back of the smoke alarm, sometimes it tells you which beeps mean what, anything from low battery to defective unit.

Stratmando · Oct 1, 2009, 06:24 AM

Best to clean and install new battery and hook up to AC. If cleaning does not help, Replace.
Smoke Detectors Save Lives.