Smoke Detector Beeping and Chirping

by Dave The Handyman on December 2, 2009

If your smoke detector is constantly beeping every 30 seconds or so then this more than likely means that it is time to change your batteries in the smoke detector, that is if you have a battery operated smoke detector beeping. There is a good rule of thumb that you should always be checking your smoke detectors to ensure that they are working properly, and you should replace the batteries in your smoke alarm twice a year to be on the safe side. If you do this not only will this ensure the safety of your home and whoever is in it but it will also stop smoke detectors from beeping at 2am in the morning, which is when they always seem to start beeping and going off.

What Kind Of Batteries Do Smoke Detectors Use?

This depends on when the smoke detector and where the smoke detector was made. In my experience most of the new models of smoke detectors us 9 volt batteries, while some are hard-wired, and some are a combination of both. If there are any new smoke alarms that are out there that are different than this I would like to be made aware of this as it is not my nature to give out false information.

Smoke Detector Keeps Beeping After Battery Replacement

Some smoke detectors will keep beeping even after you replace the battery for a couple of reasons. The number one reason a smoke detector wont stop beeping after you replace the batteries is that the batteries are bad. Batteries do go bad if they are stored for long periods of time or now in there package. I have many years experience working in an apartment complex and many of my technicians have had the same problem with a smoke detector chirping after installing a fresh new 9volt battery.

But there are some smoke detectors that need to be reset. This is what I do every time I replace a smoke detector battery and being that I have worked maintenance at a complex with 500+ units I do this almost every single day so I know what the hell I am talking about. Take the smoke detector down and remove the battery. Push the button to test the smoke alarm without the battery in it, guess what, you will here a beep! This is because the smoke detector still has a little bit of a charge from the worn out battery.

Push the test button again – you will here a small chirp or nothing at all. Now the smoke detector is reset, insert the new battery and test. This works for me 99% if the time, as I said before I service smoke detectors for a living. Now there have been a few times when I ran across that smoke detector that won’t stop beeping after battery replacement. If you tried to reset the smoke detector like I said above and it is still beeping, just trash it and get a new one. Smoke detectors are recommended by many professionals to be replaced every 10 years, some less some more, but this is when you know for sure that it is time to replace your smoke detector, you do not want to take any chances when it comes to the safety of your home and your family.

Hard-Wired Smoke Detector Keeps Beeping

If you have a smoke detector that is not battery operated and just hard wired and it keeps beeping, then you may not have any power to the smoke detector. Ensure that the breaker to the smoke detector is on and working, you can check this with a volt meter, or most smoke detectors will have a power indication light on them also.

If you have any questions about a beeping smoke detector that I did not cover or have something to add then feel free to leave a comment.

{ 133 comments… read them below or add one }

cc January 5, 2012 at 12:42 am

The above suggestions of Dave the Handyman make sense and might solve the classic type of beep sounds but the above numerous examples of folks who use a smoke detector (hard-wired or not) combined with my own experience have led me to the conclusion the “smoke detector” product seems to be poorly designed, at best. If so, then the manufacturers of smoke detector products should seriously review and thoroughly understand the above problematic events of their faulty products and then design, develop and market more robust products for all of us. It is totally unacceptable for this VERY annoying problem to continue without being fixed. Have the various manufacturers evaluated the impact of the quality of air (composition, airflow, negative/positive charges), fouling-up of the sensor due to dust/dirt, insects’ deposition, etc. etc.? If Yes, then what is their fix and respective recommendations???? Someone could write a PhD thesis on this issue. I am so sick and tired of this VERY annoying issue, that I plan to install brand new smoke detectors in our home and hope and pay that I will have some PEACE at nights for even a little while!!!! Amin!!!!

Zozo's Mommy January 5, 2012 at 1:51 pm

There are 7 smoke detectors in this house, and changing the batteries is an event to be planned for and dreaded. Both my cattledogs are rescues with some severe fear/panic issues. The chirp of a smoke alarm with a low battery anywhere in the house caused them to hide, shaking and scared. Thanks to your comments above, all batteries were replaced fairly quickly, without the usual post-ladder-storage beeping. I also identified two units that need to be replaced. I appreciate your detailed instructions more than you can imagine.

Anita Bourbon January 10, 2012 at 4:12 pm

thank you

teresa santell January 19, 2012 at 8:35 pm

we have a chirping smoke detector. we changed all the detector’s batteries; still it chirps. we changed the back up battery; still it chirps. the house is 4 yrs old. we tried changing the detector itself, but it was screwed and glued to the sheet rock, so could not remove it. they are not on a dedicated line. what next?

teresa santell January 19, 2012 at 8:42 pm

ps, the detectors are also hard wired, only one chirps unless it is disconnected then they all chirp.

Meaux January 22, 2012 at 11:53 pm

Just changed out to new batteries, each smoke defector beeped two more times in the following 5 to 10 minutes after installation as they reset themselves. Mine are hard wired & require 9volt batteries. I always seem to forget this 2 more beeps is a confirmation of sorts.

TERRY HEMMEN January 24, 2012 at 3:06 am

Thanks to Dave for his expertise….It was driving me mad after installing new batteries in my 6 detectors and still have them chirp….so, I took the unit(s) off the wall..unplugged the electrical connection..removed the batteries…pushed the test button until they lost their chirping….put the battery back in…tested it…plugged the electrical connection and remounted…problem solved!!

Lena January 29, 2012 at 2:39 pm

Why did my smoke detector start beeping when the batteries were testing still in the green good range on my battery charge tester? Shouldn’t they only start beeping once the batteries are completely dead? We took the batteries out of two of them to sleep through the night and thankfully the beeping stopped. We’re not sure if we are hearing something in the attic. Could that be affecting the wiring of the smoke alarms?

tony January 31, 2012 at 6:45 am

You solved my problem.
Good night.
Thank you.

terrie britton January 31, 2012 at 6:10 pm

We have a house that is about 1 1/2 yrs old…in the middle of the night the hard wire/battery backup smoke detectors go off randomly..the electrician came back about 6 mos ago and supposedly replace them..they are still going off…always in the middle of the night…any suggestions.

l hatcher February 3, 2012 at 2:39 am

I changed batteries, pushed testing buttons, drained power, but the alam is still beeping. please help.

Mike February 27, 2012 at 11:35 pm

Thanks Dave, It turns out that your suggestion of taking the battery out and hitting the reset button a couple of times solved the problem. I was getting worried I’d have to replace the detector, but now that annoying chirping is gone.

kent_breathe March 11, 2012 at 2:02 pm

Dave, we have a smoke detector that beeps only at night. I’ve changed the batteries and tested the ones going in and they are good (this is a hard-wired detector). Once the sun comes up, it stops. Any ideas?

Laurie March 16, 2012 at 6:41 pm

Thank you! I thought I was resetting when I pushed the button with the new battery in but it kept beeping. So, I took the battery out, pushed the button twice, installed the battery and no more beeping.

INSANE FROM THE CHIRPING March 22, 2012 at 4:38 pm

When trying to replace the detectors that are hard wired in, TURN OFF the power to the detector, if you are having trouble disconnecting the wire harness. Or else when using a screw driver to help pry it off….SHOCK O!!! Not fun when on a ladder! To stop the chirping while locating the breaker, leave the door to the battery opening, OPEN! This should stop the chirping while you regain your sanity and replace the detector! Hope this helps someone else!!!!

DD March 25, 2012 at 4:19 pm

My wife and I and young son just moved into a fairly new home. The previous owners had hardwired smoke detectors (Kidde 1200 series) installed and after the 12 hour day moving in, we noticed the faint chirping of one of the detectors. Too tired to deal with it that night, “we” (me) decided to check it out the following day. However, neither one of us could find where it was coming from after investigating every possible room. This went on for days until yesterday, I resolved come hell or high water, I was going to find this thing. We finally pinpointed the sound to somewhere under the floorboards. So, I took my flashlight and a new 9-volt and headed for the crawlspace underneath the house. After 20 minutes, I finally honed in on this *$%&# thing. Smiling at the prospect of putting an end to maddening chirping, I replaced the battery awaiting the beautiful silence. But, it still chirped. I tried the test, then hush buttons. Nope. Finally, I unscrewed the unit and unplugged it. Still chirping from the base! Heading back up the stairs, I checked out this forum, but sadly, nothing. I decided to call the local fire department and after 20 minutes on the phone with one of the firemen, he asked if there was an alarm system in the house. There was, but confused at what a burglar alarm had to do with the smoke alarms. I headed for the panel and sure enough, there was a reset code for fire detectors… and at last – golden SILENCE. Maybe this was an obvious oversight, but it never occurred to me to check the alarm system. Anyway, hopefully that tidbit helps someone else resolve their own noisy nightmare. Good luck.

Nathan April 3, 2012 at 11:24 pm

So, It’s wired with battery backup. I’ve tried 4 new batteries out of 3 different packs. I’ve made sure the breakers don’t have an issue. Still beeping. Everything else looks fine with it though, the lights on, no issues. When I hit the test buttons it works like normal.

Still need a new smoke detector?

K May 1, 2012 at 12:54 am

My smoke detector just started beeping. However it is high up on a 20 foot ceiling. There is not way I can get up there to change the battery. What will happen if I just leave it alone? Will the chirping eventually stop once the existing battery is completely dead?

Val Haldeman July 8, 2012 at 10:53 pm


All of my smoke detectors ( I have eight of them) were 10 years old so I went out to purchase new ones. All of the smoke detectors are hardwired with a battery backup. I tried to replace one in my bedroom and I took the old one down and connected the new one and the alarm went off and off and off and I can’t stop it from going off. Not just a chirp but full on alarm blaring and hurting my ears and my kids ears. Please help me!!!

deborah September 13, 2012 at 11:13 pm

I have gotten new batteries for 2 smoke alarms, now both smoke alarms are twirping and won’t stop why? Only 1 was twirping before? help….

joe bartolotta March 18, 2013 at 5:08 pm

I am aware of your discharge technique for a hard wired smoke detector. (remove battery, disconnect smoke detector from ac and hit reset button). I propose that instead of all that work, I can remove the battery, throw the circuit breaker to off, and simply hit the reset button, then install new battery, then turn on the circuit breaker.

Will this work.

Doro March 27, 2013 at 11:59 pm

Well, my situation is pretty unique. Would love some help, some answers. We have 5 interconnected hardwired smoke detectors in the house. A couple years ago the one in the hallway starting beeping. We took it down. As we still had 3 in the adjacent bedrooms we thought it was fine. Recently one of them in the adjacent bedrooms started chirping. Took it down. It stopped the chirping in the bedroom, but it started chirping in the hallway, where there was no smoke alarm attached. Have tried many things- shutting breakers and main off. Still chirps. Sounds like it is coming from the attic. We went into the attic and found the box, funnily the sound right at the box is about a third as loud as it is in the hallway. There is nothing attached to the electrical box, just the wires- nothing like a separate alarm.

The chirping has been going on for days now. (We wear ear plugs in the house). After 3-4 days it started chirping in addition to at the hallway smoke detector box, in the kitchen area where there is no alarm at all. After another few days the sound we also into the dining room. It seems to be coming through the hvac ducts.

Even though we have loose fill insulation in the attic we have been able to follow the wiring from the hallway almost to the breaker box on the outside of the house. There is nothing but wiring- no added alarm.

An electrician, who is also totally puzzled at the situation, checked around the house, garage, and basement for the presence of some kind of battery back-up transformer that perhaps the alarms are connected into. The only transformer in the attic is 15V for the hardwired doorbells.

Any clues or idea?? Thanks so.

Doro March 28, 2013 at 12:01 am

Oh, forgot to mention that none of the detectors have battery back-up. They were not made with them. And that all the alarms have been taken down. We have no attached smoke alarms and have this chirping about every 40 seconds.

It is not the CO2 detector.

Dave July 9, 2013 at 11:26 am

My smoke detectors chirp once or twice every 12 hours or so. All batteries have been replaced and they are also hard wired. I tested them and they all work fine except for the annoying one or two beeps at 0300. It is always about 3am and sometimes in the afternoon. Any suggestions?

Stacey July 22, 2013 at 6:17 am

Why do smoke detectors that are NOT hard-wired just attached to the wall ( no electricity) beep?

jody magee September 2, 2013 at 3:25 pm

Hey, after checking the power left in the battery, and particularly before you call an electrician to replace the thing, open it up, Take out the batteries, and give the smoke detectors’ contacts a good scraping with a sharp object like the sharp end of a knife … do the same with the batteries. MORE OFTEN THEN NOT, AND SOMETHING THOSE WHO CAN BENEFIT ($) FROM SOLVING YOUR PROBLEM DON’T TELL YOU, is that the contacts both detector and batteries, over time, oxidize a bit, and the slightest oxidization can prevent proper contact between the batteries and smoke alarm’s contacts. Go get’m! vb, The Garden Walker

Brent Ferguson March 29, 2014 at 6:08 pm

I had wired smoke detectors, and replaced all of them with battery operated ones. All of them worked correctly except one… it keeps chirping every 30 seconds. I replaced the batteries, and reset the detector… still chirps! Please help!! Do I need to do something with the existing wires??



Bill Caravello July 17, 2015 at 11:46 pm

I have 5 hard wired with battery backups. 1 of them keeps cherping every 45 seconds. I bought a new dector and followed all instructions. Still cherping, so I took it down and disconnected the hard wirering, still chirping. I don’t know what else to try. I am 80yrs.old with hearing aids soI can take them out but my wife doesn’t, it is driving her nuts can’t sleep. Please help.

Pat Conway June 22, 2017 at 6:31 pm

Bought new battery and reset detector as instructed but still beeping at long intervals.

Jodie Hebert July 11, 2017 at 9:22 pm

I am laughing hysterically at some of these comments because the noise got so bad in my Town Home that all detectors are down with wires hanging! Now, I am selling and have to reinstall. Maybe some of these tips will help.

I am also fearful that at the new property with the 12+ foot ceiling it will be impossible to change the batteries!

Jodie in LA

Dave The Handyman September 12, 2017 at 1:11 am

It is an indication that the battery is going low. Sometimes you can silence them for a day or so by pressing the button but as the batter in the smoke detector gets weaker it will start beeping until removed or replaced.

Dave The Handyman September 12, 2017 at 1:12 am

Replace the smoke detector.

Dave The Handyman September 12, 2017 at 1:15 am

Yes this should work.

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