Sometimes detectors are installed in attics. Such a detector could continue chirping on the internal battery power.

They will beep for a while once power is removed. When my house was being built and before we put the batteries in them, they powered up the circuit and then removed power and they beeped for hours.

That high frequency infrequent chirp is extremely hard to localize.

I checked the attic and there is no detector there. I turned off the power again and will leave it off for a few hours. How long does it take to drain the power?

I had a similar problem and was going crazy. Turned out to be a rogue plug-in device next to a piece of furniture...and I could have sworn the chirp was coming from the ceiling detectors.

"I checked the attic and there is no detector there. I turned off the power again and will leave it off for a few hours. How long does it take to drain the power?"

Take all the batteries out (every unit) also or they will power the units for a LONG time.

The batteries have been out of the units for 24 hours. And the units have been unplugged from the ceiling for 24 hours too. I turned off the breaker to the units for 3+ hours today too (until it got too dark and I had to turn it back on because they also control our hall lights).

Homebound, what kind of device was making the noise? I have checked the house for Carbon Monoxide detectors and there are none. We unplugged an amp in the room thinking that it may have been causing interference but no change in the beeping status.

Thanks for all your suggestions and help!!!

I think our problem wall device was a CO monitor, but don't recall.

Anyway, here's a thread that has some suggestions (cleaning with a blast of compressed air is one). Good luck.

http://www.thriftyfun.com/tf64963165.tip.html

"There is no possible way there is an extra smoke detector up there. "

Two years would be just about the amount of time for a battery to die on a smoke detector if someone dumped it above the ceiling during a remodel.

Just a thought.

That's what I was thinking, Kurto....I'm going to have my contractor check it out when he comes out. How would one go about finding something like that without taking off all the drywall??? Ugh. I need an x-ray for my ceiling!!!

OK, we're almost positive is has to be an extra smoke detector that was left in the ceiling somewhere, although we have no idea how and why that would happen. The clincher came when we walked outdoors next to the bedroom in question, and heard the beep as loud as we did when we were in the bedroom. Sure enough, there are vent holes from the ceiling space that are carrying the noise outside.

Now the question is, what the heck do we do with it?! How long will it take for those batteries to die?!!!

Hey - drywall is not hard to fix.

Go to local automotive parts store; purchase a low cost engine noise stethoscope.

Now, listen to your ceiling, and determine the loudest area. Use a stud finder, and determine the celing area joists position.

Using a jab saw, or a jig saw with a small blade; cut out area of drywall where the detector is located. Remove detector.

Patch drywall. NOT hard at all. One of the easiest DIY jobs.... Drywall Books are readily available if you need one to start you out.

Put new battery in detector; and determine where you are going to mount this unit to help increase house safety.

It may take from one week to six months for the battery to completely die.

Great suggestion Dave777! My contractor is coming out today and I will suggest this to him.

We can't wait 6 months for the batteries to die - this is in our guest room and no one will be able to sleep in there with the beeping....

MYSTERY SOLVED!!!! Kurto was right - it was indeed an old smoke detector that our contractor's guys had left in the ceiling of our guest room. He came out today and took off the light fixture and luckily it was within reach of the opening. One of the workers must have set it down during demo and forgotten about it. He said he had never had that happen before.

Thanks for all your help and suggestions! My house is quiet once again - bliss....

OMG....my phantom beeping....was my CO detector located just below the smoke alarm I completely removed in an effort to eliminate the problem and hours spent in the middle of the night. Reality...an easy fix...new battery in the CO detector.....feeling pretty stupid.

Thank goodness for google and finding this thread! Our weeks of "phantom faint beeping" (because I finally unplugged and physically removed a hard wired smoke detector in a guest bedroom and it was only heard in the middle of the night because of ambient noise muffling the sound during the day) mystery has been solved. It was a CO detector in need of a new battery that had been unplugged from a wall and put into the bottom drawer of an armoire when we were moving furniture. Such an easy fix and interesting that it is very hard to determine the exact location of the sound.

So after three days of on and off chirping i FINALLY figured it out!! Pulled my smoke alarm down from the ceiling removed the battery and the noise was still coming from the ceiling junction box. Arguing with my wife that it’s impossible for that box to be making noise. Replaced all the batteries and went in the attic and looked around. Couldn’t find anything. Disconnected my unused home alarm system and disconnected the backup battery. Finally came home from work and was watching the detector to see if it flickered red when it chirped and that’s when I seen it. The carbon monoxide detector behind the tv stand!! Took it into a different room and sure enough it chirped. I thought about smashing it with a hammer just for pure satisfaction but i replaced the battery and put it in the kitchen. Moral of the story is usually the easiest fix is the obvious explanation

I have this problem and chirping will not stop(every 45 seconds). I cut wires to the smoke alarm and removed. I do not get while it still chirps every 45 seconds, very annoying. Can anyone help me

You cut the wires? I sure hope you shut off the circuit breaker before you did that. If you cut them with the power on, you can give yourself a potentially fatal shock.

If you're removed the battery and it's still chirping, give it a few hours, and it should eventually stop. If not, just put it in front of a wheel of your car and drive over it. :)

Then have an electrician install a new compatible smoke alarm.

If it still won't shut up, try putting a piece of metal, like a paper clip, across the terminals inside the detector where the battery used to be.

One of my smokes started to give the low battery chirp one day. This is my clue that it's time to go around and change the batteries in all of them. So, I'm just climbing down from the ladder having put a new battery in the last one and I hear the chirp again. What? I try to figure out which detector it's coming from and I can't localize it. Then I realize my crazy parrot is mimicking the noise.

I had to troubleshoot a Cartell driveway system once and the thing was still chirping intermittently when it was de-energized. The problem was the pet bird.

Thank goodness for the internet. I had the same thing, was sure there was a phantom unit in the ceiling of our newly built house. After reading this thread, remembered I had been placing a sensitive CO unit around the house to check low levels everywhere, but had unplugged it and placed it in the mud room drop zone. The internal battery of that plug in unit must have kept it going for the week since unplugging it. The beep was bouncing off the drop zone and completely sounded like it was inside the ceiling. Mystery solved (after a couple of hours hearing a chirp every 45 seconds and going up and down the ladder with different batteries). Quiet is so nice!

I have the mystery beep. I have 7 hardwire detectors all have been removed and their batteries removed and drain. I shutdown all power at the breaker yet I still have the beep.

help!

It can take a long time for the smoke detector (even after you pull the battery) to lose the charge in the caps that generate the beep. One thing to also check is to see if you have CO detectors around. They'll do the battery beep as well. And heaven help you if you have a parrot like mine.

I think I have the same issue...maybe not but I need help!

Chirping sound coming from the junction box, no actual smoke detector unit, just the wires exposed in the ceiling junction box. Where could that chirping be coming from??? It's been 3 days now and driving me crazy! Even when I shut off all of the electricity to the house it still chirps. Help! Please

Exactly what’s happening with us and for 3 days now. What do we do???!!

Me too! the detector is off, but I hear the chirp out of the place where it was!!

Update! Found a co2 monitor near it!! Glad I read all the answers above

Oh my gosh!! Thank goodness I found this thread!! We have had a phantom beeping every 30 seconds for about 3 months now!! It’s been driving everyone in the house crazy. It ended up being a hardwired smoke detector that was disconnected when we had the interior of our house painted. We capped off the wires and pushed them in the wall and the painter put a wall plate over it. I’m sure the beeping started sometime after that and it sounded like it was coming from where that smoke alarm was. Then at times it sounded like it was coming from a different place in the house. We have 18 feet ceilings and one heat sensor located on the ceiling so wondered if it was coming from up there. Anyways, after reading this thread I went searching for the smoke alarm that was taken down when we had the painter here and I found it in the drawer of our tv stand and the dang thing was chirping away! Thanks everyone for the different suggestions. Now my husband will think I’m a genius haha!

I had what I thought was the exact same issue, it turned out to be the battery in the carbon monoxide detector that was in the same general area. Sounded exactly like the smoke detector does when the battery is low. Hope this helps!

My goodness, We had the same problem as a number of you — intermittent "chirping" every 45 seconds from a mysterious location. I removed every possible smoke detector (unplugged from ceiling) as well as removed all the batteries — still chirping!!

We were 100% sure we didn't have any additional smoke/CO detectors lying around anywhere. The chirping sounded like it was coming from the ceiling, localized in one of our bedrooms. I spent three hours crawling around in the attic, digging through "cotton candy" insulation, trying to find a dying smoke detector that may have been left up there somewhere. What a nightmare!

Turns out, my wife had left a spare CO detector sitting in a basket atop our bookshelf. She had sworn we didn't have any of the damn things anywhere.

The way I finally found the thing was by using a free decibel detector app on my smartphone. Every time it beeps you read the meter and then move closer to the sound (getting warmer!) -- finally after 4 days of chirping I figured it out.

Not a great experience.

Our mystery chirp also turned out to be the separate CO2 detector we had plugged in near the smoke alarm, I thought was in question.

I live in a condo, just another unit above me. Removed all the hardwired CO2 detectors from the ceilings, removed batteries, and cleaned 6 days ago. I still hear chirp every 15-30 minutes and it seems to come from the ceiling where the primary unit was. Any other ideas?

A lot of ? Not many

Solution found and simple. The chirp was from the Verizon Fios backup battery on the terminal used for landline phones. Disconnected it, pressed silence button, no more chirp.

2 Months with the chirping. Replaced batteries, then smoke detectors, then removed smoke detectors. So much agony. It was a carbon monoxide unit that I had in the hallway. I unplugged it during all the smoke detector troubleshooting, but left it in the hallway. At my wits end, I happened upon this site and read about the guy who had the same problem and it was the carbon monoxide unit. I ran to hallway to find my unit and pulled the battery out. Chirping stopped. Why on earth would they make the carbon monoxide detector have the same chirp as the smoke detector. It is impossible to tell what is chirping. I would rather die from carbon monoxide poison and smoke inhalation than to ever hear another chirp ever again. I thought about blowing my house up just to get rid of the chirp. Pure torture.

It's like an episode of "Wings".

I am experiencing the same thing my detector is removed from the wall battery pulled out and the chirping noise is coming from the wires in the wall where the detector attaches to ive never heard anything like this its driving me crazy and i live in a mobile home one other one did that on the same day i however somehow got that one to stop not sure how ? any one know whats causing this when my detector has nobatery and isnt attached and its chirping from the wires

This threat was so hrlpful!!!

I’m experiencing the same problem, this chirping not going away. I removed all my smoke detectors, and the chirping continued. I thought that there was an electrical problem!!

I remembered buying a CO2 detector and I could not remember what I did about, so I started searching my house around the sound, there it was. I put it outside. The chirping is gone!!!’

what a pain!!