Cleaning Smoke Alarms - Identifying a BAD Detector - Preventing False Alarms

How To Silence A Smoke Detector False Alarm

What to Do If You Have a Nuisance or Smoke Detector False Alarm Activation

The other day my daughter called me to tell me the smoke alarms in our house were going off. She told me she had been cooking but there was nothing smoking so she was confused and felt it was a false alarm.  Sometimes smoke detector false alarms occur. If a false alarm is activated, one of the following may be the reason:

The battery may be loose
The sensor may be dirty
Humidity, or steam
An electrical surge
The alarm is over 10 years old or may have reached the end of its life
Silencing The False Alarm

Always check to make sure that your alarm was not triggered by an actual smoke, CO2 or fire conditions.

Like many alarms, our smoke detectors have a Hush® feature which will desensitize the smoke alarm circuit for up to 8 minutes. Pushing the Test/Hush button on the alarm will end the hush period. This feature should be used only when a known alarm condition, such as from cooking, activates the alarm.

The Hush feature will work if the smoke is not too dense. After 8 minutes the smoke alarm will automatically reset and sound the alarm if particles of combustion are still present. The “Hush” feature can be used repeatedly until the air has been cleared from that area.

On hardwired alarms systems only hushing the initiating unit will silence all other interconnected alarms.  I asked her to check the house first, and then explained to her that she needed to find the smoke alarm that was initiating alarm unit she could silence it.

Finding the Initiating Smoke Alarm Unit - look for the alarm blinking red ever 1-second

Smoke Detector False Alarm – No Smoke

That very next morning at 5 am the smoke alarms went off again. Now I realized that it’s was not my daughters cooking but the smoke detectors must have a dirty sensor.

Smoke Detector False Alarm is most commonly caused by something interfering with the sensor. Dust buildup, cobwebs or bugs can trick the sensor into a false alarm or cause a malfunction.

My current smoke alarms are a photoelectric and CO2 combination alarm. I replace my smoke alarms every 10 years [Recommended] and these units are 6 years old. So I’m sure they need cleaning, and if that doesn’t work then replacement.

Cleaning the Smoke Detector

To clean, after disconnecting the alarm and removing any removable battery: hold the unit by its edge and thoroughly vacuum out the gap between the front cover and the backplate all the way around the perimeter with the crevice tool attachment of a vacuum cleaner. I also use a combination vacuum and compressed air and blow air through the same gap.

This is a great time to replace the battery. Once done reinstall the smoke alarm and see if you’re efforts worked. If you continue to get a smoke detector false alarm, replace the unit. See Updating Your Smoke Alarms

[dawnc]

Thank you for sharing this information! Our alarm was installed, new, last November. The date on the alarm is march 2022. It was purchased last November from Lowe’s. This morning around 5:30 the alarm beeped twice. 20 minutes later, it beeped three times. We looked around and didn’t see or smell any smoke, then tested the alarm. When tested, it chirped three times. I wish the company had 24 hour call line, however, I thankfully found this video! Smoke alarms going off are no joke and not understanding what’s going on is unsettling! Hopefully this cleaning method solves the issue and we can know our alarm is safe again!

[madelinepark]

okay so its been 10 hours or so since I vacuumed each unit for 10 mins each and no sounds. AMAZING. Thank you for saving my sanity!!!

[karenflores]

watching this because the alarm went off in my room while i was sleeping on a Sunday at 6:30am.

[Pembroke.]

Don't you love when they go off before your alarm clock? However many years I was living in a house where the basement had a strong odour emanating of sodium and sulphur; bad enough that it killed 2 smoke alarms. I ended up moving for this from the residence weeks later as the smell was getting stronger; I never did find out the root of that smell. The house sits abandoned now which is sad as it was a nice old house that made your eyes burn, have a nice weekend Rob.

[z.stone]

I'm having a an intermittent slow beep, so I started watching videos. Yours is the most informative! I now know what to check, and how to clean it. I replace the battery twice a year--when daylight savings time starts and ends. Mine are hard wired. Thanks for giving me the proper cleaning method! Never thought to do more than the outside! Thank you! And, I both 'liked' and subscribed!

Edit: I made the preparations to climb the ladder and clean the chirping detector. First, I turned off the ceiling fan and waited a few minutes before starting. A few minutes later, I realized I no longer heard the chirping! Don't know what happened but I'll keep the fan off fr now!

[mikeknevelbaard]

Finally a good video on false alarms, thank you very much. I wish I found this one four videos ago.

[njproductions]

Thank you for this to the point, practical video on how to resolve this issue. Will troubleshoot as you suggested and go forward.

[tominater]

Thanks - great video. Ours went off last night at 3am, currently disconnected will be cleaning today.

[zhelko]

thank you, i just had one go off last week and thought it was the battery but it wasn’t. fixed it only after blowing some air through it

[J_LOVES_ME]

We have the hardwired Kidde alarms and they are all linked together. At 2:30am they went UGH! Thankfully it only lasted about 5 minutes then stopped. I was sound asleep and stumbling all over our 3-story house looking for fire evidence (there was none). Now today I need to figure out what happened and make a plan in case it happens again. I just replaced them about 2 years ago, so they are still well within the 10-year period. Thanks for the video, now at least I know how to identify the one that is starting it, and I know how to hush them.

[thebnbaldwin]

Great post. Smoke detectors are a mystery to most and, there is really a lot to know about them and, fire code. I replace a couple of batteries for a client recently and had to stand on the top rung of my 20' extension ladder and stretch to get the battery out with my finger tips. No OSHA inspectors were present. The home owner was smart enough to purchase 10 year lithium batteries, thank God! But it raises the question, what in God's name are these architects and builders thinking, putting them up that high in the foyer walls?!!!

[sirbobdesign]

Best Video I have found.... most are Chip/battery fixes. My alarms are wired.

[denisek]

Great video. To the point and well-explained. Thank you!

[bestherc]

I almost have a heart attack. At 5 am in the morning the fire alarm went off and after running like a chicken without head we found out it was my bedroom. Picture this, I am 69 years old my daughter 26 and I have 3 dogs and 3 cats and no man on the house. We disconnected the battery and when we were able to calm down enough to get on the Internet and I found you. Though I am 69 I do lots of handy work at home but electrical work it is my boogieman. It is going to be hard to go back to sleep. Waiting for daylight and I will do what you suggest. Thank you very much.

[peterguzman]

Peter great video, great info . just what i needed, thanks

[ccarcohen]

Why would a low battery cause a false alarm? Is it beyond the technological capability of the manufacturer to design a device that doesn't generate false alarms when the battery is low?

[JonDoles]

I purchased 5 replacement Kidde Smoke Detectors. Three of them are false alarming. They are brand new. I’ll try you suggested cleaning method.

[dylanchalmers]

@ConcordCarpenter there's two theories on why mine went off. one is i use an old flat screen pc monitor for a tv so it's circuit could be fried and started smoking a bit and it's also become unreliable

[maxmax]

It's so strange. Why it always goes off at middle night? LOL

[luonguyen]

The video didn't help me because I have the hard wired type. To remove the detector to clean it as shown in the video means turning off the power, disconnect the wires before the detector can be removed. And of course reconnecting the wires after cleaning ... too much hassle. I just used the vacuum cleaner's extension tubes to reach the detector and vacuum around the circumference of the detectors and the small opening on the face of the detector. However that did not solve the problem. I had a second false alarm the very next day after cleaning. Since humidity could be the trigger I had tried to reduce the humidity in the house by dropping the temperature setting on the air conditioning (humidity dropped from 61% to 56%). So far so good.