It can drive you to distraction, the constant unexplainable beeping of an electric smoke detector. Often it just needs the battery replaced but it may be a signal that it needs greater attention. This is a guide about troubleshooting ideas when an electric smoke detector won't stop beeping.
My hardwired smoke detector keeps beeping. I tried turning off all breakers, but it still beeps. I tried vacuuming the unit and wiping, that didn't help. It beeps about every 60 seconds. I disconnected the detector from the wiring, but it still beeps from the hardwired sensor. How can I get it to stop?
By Wayne L
May 16, 2011
Some hard wired smoke detectors have a battery in them for back up if there is a power failure. If the battery is running low the smoke detector will start making a chirping sound just as you described.
By Nirab G. 1
Why does my fire detector keep beeping when I am sleeping and everytime?
November 15, 2015
If it sounds like a chirp it means batteries need replaced. If it sounds like the regular alarm you may need to replace it assuming it's the kind that takes batteries. You don't want to get in the habit of ignoring the fire alarm sounding in case of a real fire!
My hardwired smoke detector is going off at the interval of every few hours. When one started the other two followed. All three are over 10 years old?
By Monica T.
January 30, 2014
All smoke detectors are supposed to be replaced about every 8-10 years, so you're due. New smoke detectors run about $5-$20, so it's not too bad, even for 3. I'm sure the fire department has a program to help if needed.
Some smoke detectors do take a 9-volt battery that can be replaced, but those usually chirp when the battery needs to be replaced - not go off. Even those should be swapped out every 10 years, so I'd still recommend replacement.
Another thing that can make some smoke detectors go off is if they get a lot of dust in them.
January 30, 2014
It is time to replace them. I am a fire fighter and depending on the type, they are to be replaced every 8-12 years.
I have a beeping smoke alarm without a battery. I want it to stop beeping, what do I do? I have turned the power off and I have disconnected the plug from the back of the alarm, but it still won't stop beeping. What can I do?
By B C
August 7, 2012
Fixed the same problem thanks to my volunteer fireman neighbor. Vacuum the works. It probably does not even look like it needs it. New battery and you should be rid of the problem.
Our electronic smoke detectors are going off during the night hours. This has happened last night 3 times. It is a warning beep because of a low battery. Does anybody know anything about this?
By Mark from Stafford, VA
June 29, 2011
Is your smoke detector also a carbon monoxide detector? I know with our smoke detectors the beep for a low battery is different than a beep for an alarm. My mother-in-law had a man come out for her stove and he said she had a severe gas leak, but nobody could smell it, but him, so it might be that and you just can't smell it.
There's about 6 fire alarms in my house. One alarm started going off then, all the other ones went off for about 30min. Finally it all stopped, but then started again. Now that all the beeping stopped, one continues to beep every minute.
I changed the battery and it still beeps, so I flipped the battery figuring it was in backwards. The darn thing still beeps, I pushed the test button and that didn't work. I don't know what else to do, and I need some sleep. I'd cut the power, but it's my grandparents house so I don't want to do anything I'd get in trouble for. Any advice would help.
By Rose M.
May 25, 2011
I had the same problem with a fire alarm in our two bedroom apartment that continually beeped in our living room. One of the maintenance men had to remove the alarm and install another one.
It's not always the battery, maybe the alarms need to replaced with new ones. The alarms in your grandparents home are probably the original ones.
When you have put new batteries in your electric smoke alarms and they won't quit beeping who do you call for a problem like this? Or what can you do?
By Lynda from Bloomington, IN
April 8, 2011
My friend had that problem and had to call fire dept hers just went off in middle of the night it turned out it was the wiring, it did take the fireman quite a bit of time to figure that out and they said they learned from coming out to her home.
Good luck to you.
I have detached the smoke detector from the ceiling electrical contact, but the chirping continues without stopping.
By Andri from San Diego, CA
December 27, 2008
There are two "types" of smoke detectors. One type detects smoke and the other type "sees" fire. Either of these 2 units do not have a long life span only about 5-7 years. Just because the smoke detectors "beeps" does NOT prove the smoke detectors are in functioning order. The only way to test the smoke detectors is going outside and lighting a fire (log, newspaper etc.) away from any buildings and then slowing bring the smoke detector near the smoke and flame to hear if the smoke detector alarms. If no alarm sounds the smoke detector must be thrown away and a new one purchased, usually less than $10.00. More than 5,000 people die each year in house fires, most could be avoided if the smoke detector worked. PLEASE check all of the detectors in our house. Your life is worth more than a few bucks.
P.S. Where is your fire extinguisher? It should be placed near the exit of your house or work. NOT IN THE KITCHEN! If the fire is in the kitchen how would you reach the fire extinguisher? As you are exiting the building and the fire extinguisher is near the exit and you believe you can put the fire out then use the fire extinguisher at hand. Remember this acronym - PPS Pull the pin, Point the nozzle, Pull the handle, Sweep the base of the fire. If the fire is not contained get the heck out of the building, NOTHING in the building is worth your life.
By guest (Guest Post) Flag
January 7, 2009
Here is some detailed help for those of us who are "mechanically challenged."
First, check your carbon monoxide (CO2) detector, if you have one, to make sure it is not the one beeping. (If it is, open windows to air out the house and get some help to fix the problem.)
Second, make sure the temperature in your home is within the tolerable range for your detector. (Mine has to be above 40 degrees F, and below 100 degrees.)
Third, change the battery. (Some steps below may not apply to your smoke detector, but hopefully this list will help anyway.)
How to change the battery:
Look where the alarm is attached to the wall, and remove the little plastic "stick" that is stopping the alarm from being turned, if present. (Mine had one in a slot on the right side. It just pulled off.)
Turn alarm in the direction of the arrows on the front of smoke detector. (Mine only turned a tiny bit, clockwise, then I had to pull the alarm straight away from the wall.)
It may be connected still by wires to the wall (or to a hole in the wall actually.) Squeeze both sides of the plastic piece where the wires come out of the back of the alarm and pull straight away from the alarm to remove the plastic "plug" holding the wires.
Now, hopefully, you can open the battery door to change the battery. My battery compartment had a piece of plastic (like a stick) on a spring that popped up when battery was removed. I had to push the plastic stick down into the battery compartment, then push the new battery on top of it so the battery door would close.
If it still beeps after you change the battery, try flipping the battery over. If it still beeps, try a different, new battery, and try it flipped over if needed.
If it still beeps then you may have to buy a can of compressed air to blow the dust out, OR buy a new smoke detector, whichever is cheaper/easier.
I hope this helps others to avoid the hassle I had to figure out how to change the stupid battery. Mine is still beeping so I'll try the compressed air or buy a new smoke detector once it is daylight.
I have a model 9120B smoke alarm. It chirps about every 1 to 2 hours apart. I have replaced the batteries, checked connections, and even unplugged it from the wall. I took the batteries out and it still chirps. Do you know what's up?
By Anthony from Blairsville, GA
January 12, 2012
Our volunteer fire department has suggested in the past that this is of ten because it needs vacuumed throughout the unit. Doesn't even need to look dusty or dirty. I tried it and it worked for mine. Been using the remedy ever since.
Do all hard wired smoke detectors have batteries? Mine was chirping on and off and when I went up to open and see there was no battery. Is that normal?
November 10, 2011
If you don't have a user manual, use the manufacturer and model number. Go online and search their web site to see if/where the battery is. Also there may be a help line you can call.
I recently changed the batteries in 3 hard wired smoke detectors. After about 1 day (happened twice) they all go off at the same time. Any advise please? By the way I tried holding the test button down with the batteries out but no luck.
July 19, 2011
Most hardwired smoke detectors have a signal wire which tells all to sound when one goes off. I would take one out at a time, they usually twist on their base and have a plug in connector. When you find which is causing the problem you will probably need to replace it with the same or a compatible model. The other possibility is that when you changed the battery you dislodged some dirt which worked its way into the sensing chamber and causes the false alarm. Gently vacuuming out the detectors may solve the problem.
My smoke alarm keeps beeping every 20 seconds. The battery cannot be changed for life of product. I have blown it out, but it still beeps, what more can I do?
By Rick from Wales, UK
April 29, 2011
I've never had any luck with the cheap smoke detectors. First place the battery is nearly impossible to put in. I just bought a new one a few months ago and had to take it down because of the chirping. I finally got a new battery in and it still chirps. Someone at the fire department told me they get dust in them. I blew the darned thing out and it still chirps. I'm going to get one of them that is a smoke detector and carbon monoxide detector together that plugs into the electrical outlet.
My smoke alarm keeps beeping and it won't stop beeping.
Why does the fire alarm beep for no reason? There are no fire hazards.
By Irwin W. from Danville, CA
February 5, 2014
Some smoke alarms beep if the batteries are dead or perhaps not put in correctly. Hard wired ones will have back up batteries that need to be replaced occasionally and they may beep if the are not wired properly.
There are some alarms also detect carbon monoxide. You may have a separate problem to investigate if it is a dual purpose alarm.
If it truly is broken, they are not that expensive to replace. It is very important to have a functioning smoke alarm.
I know this sounds strange. We have electric smoke detectors. Are there batteries in them also? We have one that has started beeping and we can't stop it. Is there a battery in it or do we simply have to replace it? We have lived here 2 years (new) all the other batteries are OK. Our old house had electric smoke detectors and they never went bad. We lived there 15 years.
September 20, 2011
Sounds like there is a short somewhere. You need to contact a licensed electrician-he/she will have the tools and training to track down your problem. Do it as soon as you can because this could be a fire hazard; if you are on a very tight budget you can call the local fire department non-emergency number and ask if they know of any programmes in your area to help you.
The electric smoke detactor has gone off twice today. I have a heater in the room with it (a bathroom) could that cause it? Can the heat fron the heater cause it to go off? I've checked the entire house, there is no smoke. So what's the problem? The detector is very old.
By Suzanne n
My smoke detector won't stop beeping. I have done all of your suggestions. What else is there to do? P>By Judy
September 29, 2014
I assume you have changed the battery, which is the usual reason for it not stopping beeping. If you have and it is faulty it will have to be replaced.
My smoke alarm will not stop beeping and I don't know what to do about it. I changed the battery, but it still beeps.
July 30, 2013
Remove the cover and vaccuum out the inside. Dust and especially spider webs can make the sensors go off. If that doesn't do the trick, it may need replacing, as they do eventually wear out.
I changed the heat detector batteries located in my garage. My smoke alarms in the house have been going off ever since. I now have changed all the batteries in all the smoke alarms and yet, one keeps chirping about every minute and a half.
By Glenn O.
November 14, 2012
We had the same problem and it was the unit. We just replaced all of them as a precaution. No more chirping.
I have a hard wired smoke detector with battery backup. It starts beeping (not loud and not the same sound as the fire detector sound) every 24 hours. It goes on for about 30 beeps. Anyone know what's going on with it?
June 6, 2012
Try changing the backup batteries. They are probably nearly dead and the beeping is the warning to change them.
I have an alarm that beeps; are all the alarms on the same system? When one battery is dead does it effect the other alarms? Do you need to change them every year as you do non electric alarms?
By Gerry T.
I was getting ready for work this morning when all of the sudden I hear this long continuous beep coming from my smoke alarm. I opened it up, there were no batteries, and it was still making this noise. So I thought that maybe there could be a back up battery or something, so I unhooked it and disconnected it entirely, but it still was making the noise! It seemed to be coming from the ceiling. And it's still doing it as I type! Can some one help me figure out how to stop this before I go absolutely insane?
I have an Ei154TL heat detector that won't stop beeping. Why is this, when it's powered by the main as well?
October 27, 2011
I would check to see if the heater has a battery or not as that is what is most always the problem with detectors beeping for apparently no reason. Even if it is hooked up to main, it just might have a battery. (?) Or google for "heat detector beeping" & check out those links. Good luck! Definitely not something to ignore, I would think.
My smoke detectors are OK on battery back-up, but when I turn the power back on they start beeping non stop. I keep the breaker off but need to fix this soon. Any ideas? Thanks.
By Kelly R. 1
I had the same issue. My detector beeped loudly once a minute; and another one beeped once a minute, so beeps were heard every 30 seconds from 2 detectors. I vacuumed the units, turned off circuit breaker, disconnected wire unit from detectors, replaced batteries, held test button with battery out and then with battery in. None of this helped. All detectors had green solid light. I tried to solve all day and got a headache of course.
Finally (and this is noted by others too), I checked my plug-in (stand alone, not connected/wired to house or to smoke detectors) carbon monoxide detector (Kiddie brand, bought about 3 years ago; smoke detectors came with new house, now about 8 years old). I had just quickly plugged the carbon detector units into outlets and forgot about them. The carbon monoxide detector was going off! It had a red light flashing. My second carbon monoxide detector (Kiddie, same as this one) was NOT alarming and had steady green light! I unplugged the flashing carbon detector and INSTANTLY all smoke detectors were quiet Yikes! There was no carbon monoxide, I'm not sure why it went off.
So I'd suggest if you have wired/electrical smoke detectors to try unplugging various other things; sensor lights, alarms, small appliances, anything recently plugged in, etc. It might not make sense but it's an easy quick thing to try before trying complicated or expensive solutions, and to avoid headaches! Good luck!
Will an old battery cause an alarm to go off?
By C Gray
How to stop beeping in an alarm battery located somewhere else on another device?
By Mary D.
Why won't my electric smoke alarm stop chirping?
By Noel D.
I replaced the batttery to no avail. I removed electric battery backed detector from the ceiling mount. The chirp is coming from inside the ceiling, not the unit. Please help me.
By Giacomo S.
Our smoke alarm, with no batteries, keeps beeping. It is no where by the kitchen, but in the hall on the ceiling. We live in a bungalow.
November 16, 2014
The detector when manufactured has a pull tab installed you pull this tab after you install working batteries. If you pull the tab with out installing batteries or remove the batteries the built- in program beeps until you install working batteries. The detector beeps when it is not functioning properly, as it does with charged batteries. It does not do the job of protecting your household if you do not provide it with the correct care. It will also beep when the charge in the battery in too low to do its job. Please your family safe by installing working batteries and it should stop beeping until it is ready for new energy
Does the alarm have a battery for back up and if so where is it fitted?
I have three electrical smoke alarms and one keeps beeping. How do I fix that?
By Rochelle J.
My smoke detectors are electronically wired. They beep-chirp for about two hours each day and then stop. I have changed all of the batteries and have vacuumed them. Help!
August 5, 2014
Smoke alarms store error codes. If the beeping continues, and you have a wired in system with battery back-up: 1. turn off the main circuit to the smoke alarm 2. remove the detachable part of the alarm 3. remove the battery 3. with the battery OUT of its compartment, hold down the TEST button for about 15-20 secs 4. reinstall the battery, or replace it with a new one if the original is dodgy 5. reattach the alarm with battery in place to the base. 6 Turn on mains power. It will work again without chirping ('cos you have reset the error code for chirping [usually 'cos of low-bat]).
The smoke alarm sounded and there was no smoke anywhere in the home. The house is vacant and no appliances were on. I removed the one making noise, but when I reattached it, it went off again. Is it possible this one has gone bad?
By Wallace K.
The in home smoke alarms were installed when the house was built 15 years ago or so. There are four. They are AC with a 9 volt back up. They started beeping or chirping one by one. We replaced the batteries one by one, with all new batteries. I took out all the units. Two of them still chirp with "no" unit. How is that possible, maybe something in the attic?
By Charles from Bakersfield, CA
December 10, 2013
Smoke detectors have a shelf life of about 5 years. Try vacuuming out the inside of each unit because spiderwebs and dust can cause chirping as well. They may need replacement, call the local fire department. They are usually happy to come and check it out. If you have critters in your attic, they may have damaged the wiring, the main reason wired in units are not usually recommended. I am a firefighters wife.
My electric smoke detector started chirping every 50 sec. How do I stop it? Do electric ones have a battery as well?
We had an electrical storm pass through last light; would that upset something? The electric smoke alarm upstairs is okay though.
Does one have to get an electrician in to change it? I hope not!
Thanks for your help.
My smoke alarm won't stop bleeping. Why is that?
What gives with these devices, mine just keeps beeping no matter what I do. I have changed the battery and blown it out. Can someone please assist me? I have gone crazy due to beeping sensations.
By Errol F.
My smoke alarms started chirping. After trying everything suggested we finally replaced all of them with new units and they are still chirping! The connections are all tight, the batteries and smoke detectors are all new. What else could it be?
My ac fire alarm has been going off for 24 hours non stop. How do I stop this? We have done everything!
By Latricia S
How do I get the cover off the detector?
I took the cover off to clean my Honeywell smoke alarm and when I try to put the cover back on the alarm goes off. Should I turn off the circuit breaker or just keep trying until the alarm stops?
What is happening? We changed all the batteries and even had the gas company come out to make sure there was not a carbon monoxide leek. We finally flipped the breaker and took out the batteries. We now have peace and quiet. If it is not any of the above issues then what am I missing when it comes to the constant beeping?
My smoke alarm is chirping on and off 24/7. When opening it up I didn't see a place for battery. Do you have a answer?
My smoke alarms are unplugged, the batteries are removed, the mounts are still chirping. I even turned the breaker off. I am going crazy. Help! Suggestions?
By John V
Every time we cook something the fire alarm always seems to go off. It doesn't matter what we cook. We can't even use the oven without it starting to beep. Is there a possible quick fix for this? I'm really just tempted to take out the batteries every time I cook if this keeps happening.
The smoke alarms beeps every 20 to 30 seconds, even after I put in new battery.
My combination ionization/photoelectric smoke detector keeps going off, as if we have a fire, but there is no smoke?
I recently purchased a home which was built in 2003. When I moved in I was informed by my neighbors that my smoke alarms were going off. They had to contact my realtor to have them removed. Now that I am here, I replaced all the batteries in the smoke detectors and checked them for proper operation. The problem comes when I install them and plug them into the power plug. They begin to alarm and only stop after I remove them from the power plug.
What do you believe the problem is and what do you recommend to correct it?
Jay from Lehigh Acres FL
I don't know what the problem is but if I were you I'd contact the local fire department and ask them if they have a program that checks smoke detectors. Many fire departments offer this as a free service and maybe they could either tell you the problem or recommend an electrician to fix this. Good Luck and please don't sleep without the alarms working properly. (01/16/2006)
By Connie A.
I also don't know what's wrong with your detectors but we bought a home the same year and have the same problem. We called out the fire dept. to make sure there was no fire since we had lost our previous home the year before to a fire. They told us to call an electrician, expensive for us.
I went out and bought some battery operated smoke and fire detectors and put them in the home until we save enough to have an electrician come out. The one who did gave us an estimate of $500 to check and replace what's wrong.
Being paranoid about fires, I would buy some to put in the house and would never sleep in a home without one. (01/17/2006)
My smoke alarm won't stop beeping. One alarm started to beep, I replaced the battery, then another started. I have 5, replaced all with new batteries, still beeped (about once every minute). Replaced all the alarms, still beeps, disconnected all alarms, the house still beeps. Would there be a relay, and where can I find it. Help my family is going crazy, it's been 3 days.
Kat from Seattle, WA
Before going through any expense; try cleaning each of them thoroughly; we had a small bug in one of ours that kept setting it off; with 9 smoke detectors in the house it took awhile to figure out which one was the problem; after cleaning each of them and installing new batteries problem was solved. (06/18/2008)
By Deb in AZ
I agree with Connie A. Ask your local fire dept to come and check it out. We also had that happen. My husband changed the battery too, didn't help. He also shut off the breaker that fed power to the smoke alarm. It didn't work either. We just bought a new one - they're fairly cheap now. Good luck. (06/18/2008)
Ok, I figured it out! After the 3 worst minutes of my life (it hurt more than labor) & I finally got them to stop insanely screaming at me, and they just beeped, beeped, beeped. By the way, I'll need to train the local fire dept on this, because they couldn't figure it out either.
I took all of the batteries out of them, shut the MAIN BREAKER off for about a half hour, of course I opened up all the windows to air the place out. Then I put all the batteries back in & turned the main breaker back on. No beeps for the past 15 minutes, so I think we're good. After I reset all of the clocks in the house, I'm headed to the doctor to get my damaged eardrums repaired. (08/29/2008)
If your hard wired interconnected smoke alarms are going off, the primary source of the problem should have a blinking red light. Normally all detectors have a solid green or blinking green light. Remove the offending some detector and remove the battery. This should stop the alarm. You then need to assess if the problem is the unit itself, or if it just needs a a new battery. I just had a power failure in my home, and it knocked out one of the units, which set off the whole system.
By Alec Karys
About a year ago we had a severe storm that tore a 20 ft hole in our roof. Contractors came out, and repaired the roof, drywall, and paint. Now it's as good as new. Fast forward to yesterday I'm on the computer working and my hard wired smoke detectors all start going off. I quickly ran through the house checking for fire/smoke, thankfully I found nothing. I then contemplated one of the batteries went dead so I pull all the batteries, still no luck.
Next, I went to the circuit breaker box and selected multiple GFI breakers to off position. After waiting a few minutes I switched back on the breakers and they started going off again. Being it was late on Saturday and we were not in danger of a fire I decided I would research further and possible call an electrician for Monday.
After searching the internet on this subject I've come up with the following repair opportunities:
Any assistance would be greatly appreciated. Oh yes, I'm not sure if the home damage occurring is relative, I personally don't believe so or I would have had an issue before now. Thank you.
Sstchester from Haslet, TX
Try taking a vacuum and blowing them all out. Even a cob web that has gotten in or a speck of dust will set them off. I had this problem and once I did this, but I used a blow dryer problem was solved.
We had that problem when we first moved into our house 10 years ago. The place had been empty for several years and I had cleaned it thoroughly before we moved in. However, I didn't think to open the smoke alarms and vacuum them. I do now every time we check the batteries.
It cured our problem in no time. Good luck. (11/19/2008)
We had a hard wired smoke detector go off after we'd had a new roof put on. I believe that when the old roof was off that moisture got into it from the open roof and that was coming through the attic. When the fire department was out I told them about the new roof and they told me that's what caused it was it malfunctioned due to moisture. (11/19/2008)
I believe they're supposed to be replaced every 10 years anyway due to malfunctioning, just to be safe. (12/29/2008)
I have a hard wired smoke detector system with individual battery backup. My system started single chirps every 30 seconds 3 days ago. I changed all batteries in all smoke detectors in the system, still chirps. I had an electrician come by today and he does not know what the problem is either.
The chirp only comes from the master bedroom and disconnecting the bedroom detector physically and electrically does not stop the chirp. A physical inventory of the attic above the bedroom reveals "no" box, etc. that could cause the chirp. I'm lost, need help.
Mike from Garland, TX
Yep, we had this once, it was a short in the wiring. It had to be fixed by a repair guy. (02/28/2007)
Yes it is true that shorts can develop in the wiring in hardwired smoke detectors. Would your local fire department check it for free for you? It's worth inquiring at least. A big buggaboo of smoke detectors believe it or not, is dust in the sensors. Remove the top and batteries and vacuum it out using the brush attachment of your vacuum. Spiderwebs and house dust can cause the sensors to chirp. This last advice is from my husband who is a firefighter. The vacuuming should be done to all detectors regularly, a good time is the twice yearly time that is recommended to change the batteries and do a manual check. (03/02/2007)
<img src="/images/feedback_image.lasso?id=12696079" width="370" height="308" alt="RE: Chirping Smoke Detector System">
This has happened to me, it took about a week to figure it out. The electrician actually had one of the batteries in backwards. If I were you, I would go around and make sure all of the batteries are in correctly. We had to call the manufacturer of the alarms and they said they were made like that for "security" purposes. I hope this helps. (03/04/2007)
"Disconnecting the detector physically and electrically does not stop the chirp". Seems to disqualify some of the posters' advice above.
Muffle the detector by hand. Does beeping muffle? If so, it is the detector at fault, you must have the battery in place still, follow the advice by other posters. If not, it's not this detector. It's a nearby CO detector or other nearby smoke detector. This sound is hard to localize. Maybe an old detector lying in a drawer, that you have since replaced, but still has a battery in it? (01/13/2009)
Make sure your battery has not expired. We just discovered our newly replaced battery expired in 2007 (and wondered why the smoke detector was still chirping). Replaced with a non-expired battery, two final beeps, and blessed silence; all is good. (09/29/2009)
I had the exact same problem; chirping every 30 seconds in a hard wired smoke alarm despite changing the battery and ensuring the battery was fresh and installed properly. After frustration and considering replacing the whole dang unit, it occurred to me that the battery, although installed properly, was no longer making a good connection with the two connector plates at the end where the +/- leads connect. There was the tiniest hair-breadth play or movement of the battery.
So I simply took a letter opener (or pen, screw driver, whatever), and slightly bent/pulled out each of the two metal connector plates. These had been pressed down flat over time, and the battery leads were barely touching them. As soon as I pulled them out, when I reinstalled the battery it was in really tight and the leads made a solid connection with the connector plates -viola- the chirping stopped and my problem was solved. Hope this helps. (10/07/2009)
I have a two story house and my smoke detectors are chirping every 5 seconds. I tried looking for the back up power source and I could not find one. If someone could help that would be perfect.
That usually means that one of your smoke detectors needs a fresh battery, even if they are hard wired. When one goes off, they all go off. I would replace all of the batteries. Don't forget that you might have one in your basement, too. Do all of them with fresh batteries and that should solve the problem. The batteries are backup power to the hard wiring. You also might have a detector that is hidden somewhere, like in a closet, which can be overlooked.
Just had a similar issue, when the alarm went off, I pushed the "hush" button. It kept chirping, so I kept trying different combinations of the two buttons. Eventually, I read the back of the alarm, which said that it will continue to chirp every 45 seconds for 7 minutes or until you push (and hold) the "test" button.
The moral of the story: if you push the "hush" button, you may have to "test" the smoke alarm before it will stop chirping again. Hope this helps someone. (06/22/2010)