
Do you want to stop your smoke detector chirping or giving false alarms?
If you are waking up in the middle of the night from beeps or random sirens — it can be a frustrating issue if you can’t figure it out.
In this guide, we’ll cover…
- Fixing a smoke detector chirping
- How to stop false alarms
- Common causes of false alarms
- How to deal with a carbon monoxide detector going off
- And sample troubleshooting tables
Let’s get started!
What To Know Before Troubleshooting
Shutoff Power At Breaker
If the smoke detectors are interconnected or hardwired, removing the alarm from the housing can present a shock hazard since the wiring is exposed behind it.
I recommend shutting off the breaker at the panel to be safe.
Using The Test/Reset Button
Every smoke detector has test/reset button on the front cover that can control the horn.
- Silence Or Hush Mode: Most modern smoke detectors have a silence or hush mode that can silence an alarm going off or if it’s chirping by pressing and holding the button.
- Testing It: The button can be quickly pressed once to test the alarm. If it’s already in silence mode, you may need to hold down the button. Press it again to stop the alarm. Anytime it’s cleaned or removed, test the detector afterwards.
9 Ways To Fix Smoke Alarm Chirping and Beeping
There are typically three main reasons a smoke alarm chirps which is typically one chirp every 60-seconds.
- Low Battery: This is the most common reason for a smoke detector chirping. The smoke alarm has a program that makes it chirp when the battery is low or faulty.
- End of Life Signal: Some smoke alarms beep when they near the end of their lifespan (typically 8–10 years). This means that even with a new battery, the unit will keep chirping due to the end of life program. Likewise, if you have a smoke alarm with a permanently sealed battery, the entire unit will have to be replaced.
- Malfunction: Depending on the smoke detector model, it may have a program that chirps if there is a malfunction. The beeping may be more frequent such as 3-chirps per minute or it may happen on a 40-second interval instead of 60-seconds.
There are a few other reasons why a smoke alarm can chirp, we’ll go over the possibilities below and how to deal with it.
#1. Hit The Test/Reset Button
The easiest way to quiet a chirping smoke alarm is to hit the test/reset button on the unit — also known as the silence button.
Pressing this button will temporarily turn off the chirping for around 8-hours (depending on the model) if it’s related to a low battery. If the chirping is a result of an end of life program, pressing the reset button should silence it for about 2-days or longer before the chirping resumes.
Independent Chirping
Hitting the test/reset button will only work for the individual smoke alarm that is chirping. You will have to individually locate each alarm that is making a chirp and silence it. If you have multiple alarms chirping, it likely means they were installed at the same time and either have low batteries or at the end of their life.
4 Steps To Silencing A Smoke Alarm
- Determine which smoke alarm(s) is chirping. The smoke detector may also be flashing green or red to indicate that it has chirped. Normal operation is usually a continuous green LED if it has not chirped.
- Locate the silence or test/reset button on the smoke alarm cover. There is usually just a single button on the unit so it isn’t hard to find.
- Hold down the reset button for 5-10 seconds. You may hear an acknowledgment beep when you press it down to let you know it’s in silence mode.
- Depending on whether it’s a low battery or end of life signal, hitting the test/reset button will stop the chirping for a period of several hours before it resumes chirping once a minute.
NOTE: Silence or quiet mode doesn’t shut off the smoke alarm, it just puts it into a mode that is less sensitive to triggers and it will automatically go back to normal after a period of time.
Read Also >> Where To Place Smoke Alarms? (Building Code Explained)
#2. Replace The Battery
If you hear chirping from your smoke alarm, it is likely from a low battery but there are some other possibilities as explained later in this article.
If you have a newer type of smoke alarm with a sealed battery compartment, this means you won’t be able to change out the battery and it will need replacing. The average smoke alarm has a lifetime rating of 8-10 years.
Battery Quality
Your particular smoke alarm model may also have required battery brands listed in the manual but I recommend at minimum buying a well-known brand like Duracell or Energizer. Poor quality batteries can reduce the life expectancy or cause malfunctions.
9 Steps To Changing The Battery
- Find the battery compartment. The battery may be on the side, the front, or the rear of the alarm. If it’s on the underside, you will need to unscrew the top of the smoke alarm counterclockwise from the housing.
- If the unit needs to be removed, first shutoff power at the electrical panel since there is a shock hazard if it’s hardwired.
- Carefully disconnect the smoke alarm by rotating it counterclockwise. Some smoke alarms have tabs on the side that may need to be pried open with a flathead screwdriver in order to rotate the alarm and pull it free.
- Disconnect the wiring connection if it is hardwired. The wiring usually has a quick-connect plug that can be easily detached.
- Open up the battery compartment.
- Change out the battery with a high quality battery — commonly 9-volt.
- Replace the battery cover.
- Screw smoke alarm back into housing with a clockwise turn.
- Hit the test/reset button to verify it is working.
#3. Do A Hard Reset By Draining Power
Sometimes smoke alarms need a hard reset in order to stop chirping even after changing out the battery.
It’s possible for a smoke alarm to hold a chirping program in the memory through residual power in the capacitor and other electrical components. So even with a fresh battery, the unit will keep chirping as if it still has a low battery.
- Follow the steps in previous section to remove the battery.
- Disconnect the wiring harness if hardwired to AC power. Shut off power at the breaker first to avoid a shock hazard.
- With the battery and wiring (if on AC power) removed, press and hold the test/reset button.
- Hold the test/reset button for 10-20 seconds to allow all residual power to leave the unit.
- Re-install battery, wiring connector, and screw smoke detector back into the housing.
- Hit test/reset button to verify it’s working.
- Wait and see if chirping resumes.
Read Also >> How Many House Fires Happen Per Year? (47 Key Fire Statistics)
#4. Clean The Smoke Alarm
Many modern smoke alarms will chirp if the unit is dirty.
A common culprit is renovating a home when there is sanding, drywall patching, or painting prep. The particles can float into the smoke alarm and obstruct airflow — leading to annoying chirps.
I recommend using a can of compressed air or a vacuum with brush attachment to clean the unit.
LED Light Pattern
Some smoke alarms will flash green off/on when the smoke alarm needs to be cleaned. It depends on your smoke alarm brand but any LED light pattern other than continuous green (normal operation mode) signals that something is off.
For example, the First Alert Smoke Alarm (SMI100) flashes the GREEN LED light twice every minute to signal that it needs cleaning.
Where To Clean?
The two main types of smoke alarms are photoelectric and ionization. Photoelectric units will have a light chamber or vent on the top of the unit. Ionization smoke alarms will have vent holes on the side of the smoke alarm.
You may also have a combo alarm that has ionization AND photoelectric in one unit.
These vent openings should be carefully cleaned with compressed air or a vacuum brush attachment.
CAUTION: Be careful to avoid cleaning sprays or water on the smoke alarm. If you use a damp rag, make sure it is only lightly damp and not wet.
4 Steps To Cleaning A Smoke Alarm
- Have a can of compressed air or vacuum with brush attachment ready.
- Clean the air intake port on the front of the unit.
- Clean any air intake ports on the sides of the smoke alarm.
- After cleaning, do a hard reset, drain all power from unit, and hit test/reset button (described in section #3 above).
#5: Inspect And Clean Battery Terminals
Sometimes even with new batteries, if the terminals are dirty, it can cause beeping.
If the battery terminals are dirty, corroded, or bent out of shape, it can cause a poor electrical connection which activates the low battery (or unreliable power) chirping alarm.
Dirt and debris on the battery terminals insulates the terminals and reduces the battery connection. A poor terminal connection can lead to low battery signals as the power weakens.
8 Steps To Cleaning Battery Terminals
- Remove smoke alarm.
- Remove the battery cover.
- Remove the battery.
- Look at the terminals and verify that they aren’t corroded, dirty, or bent.
- If dirty, clean the terminals with a vacuum brush attachment or can of compressed air.
- Use a toothpick or small brush to remove any stubborn debris.
- If the terminals are bent, try to straighten them.
- When re-installing the battery, make sure the polarity is correct for the terminals.
Read Also >> The 5 Leading Causes of House Fires
#6. Replace The Smoke Alarm
If all else fails, the smoke alarm may have an internal fault or be at the end of its life.
For example, the popular First Alert smoke alarm will chirp:
- Three times per minute if there is a malfunction
- Five times per minute if its near the end of life
- One time per minute if it has a low battery
Your smoke alarm may have a similar chirp frequency programs built into it.
When the smoke detector has a malfunction or its at the end of its life — there’s really nothing you can do but replace it.
Check the expiration date on the back of the smoke alarm but the information may be blank if it needed to be written down by the original purchaser.
#7. Inspect The Wiring Harness
The wiring harness or connection is what connects the smoke alarm to the home’s AC 120-volt power if it’s hardwired. Sometimes the wiring harness itself can be damaged, loose, or dirty.
4 Steps To Inspecting Wiring Harness
- Shutoff the breaker to the smoke alarms.
- Remove smoke alarm from housing.
- Disconnect the wiring harness.
- Carefully inspect the wiring harness for loose or a damaged connection.
#8. Troubleshoot Smoke Alarms Individually
Low battery chirps will typically affect smoke alarms independently. If all of your smoke alarms are chirping, it likely means that they were all installed at the same time.
If you only have a couple alarms chirping, you can look for changes in the LED indicator light on the cover. The LED light on the alarms that chirp will usually turn a different color or it will flash — just another way to find the smoke alarm with an issue.
Otherwise, you will just have to stand near the smoke alarm and wait for a chirp to verify the source.
FINAL STEP: Test The Unit
After cleaning, changing the battery, or any other troubleshooting step — make sure to test the smoke alarm.
The power LED should emit a continuous green light when it is operating normally.
Hit the test/reset button on the cover to verify that it is working. If the smoke detectors are interconnected, all alarms should go off at the same time.
An even better option is to use a can of fake smoke that can be bought online for a few bucks. It is sprayed onto the detector which I use during home inspections, read about my testing process here.
5 Ways To Fix Smoke Alarm Going Off For No Reason (False Alarms)
A smoke alarm that goes off for no reason is an extremely frustrating problem. False alarms make occupants less responsive to future alarms, the boy who cried wolf phenomenon.
If your smoke alarms are hardwired or interconnected, you can find the alarm that started it by looking at the LED light on the cover. The initiating alarm should be emitting a RED color even after the alarm has ended.
The other smoke alarms should retain their continuous green LED light pattern.
However, this ‘after the alarm’ LED pattern may only appear if your smoke alarms have AC power rather than just on battery.
#1. Quickly Turn Off False Alarm
If you are currently dealing with a false alarm, you have a few options to quickly shut it off.
- Press And Hold The Silence Button: There should be a silence or test/reset button on the front of the alarm. Hold down the button on the unit until you hear an acknowledge chirp. It may take a couple seconds. With other units, it may just be a quick press of the button.
- Silence The Initiating Alarm: Depending on your model, you may need to silence the alarm that initiated the false alarm if they are all interconnected or hardwired together. The initiating alarm will typically flash a continuous or repeating RED led light on the cover. Press and hold the test/reset button until the alarm is muted.
- Open Windows: Open a window or two to allow more air circulation in the room.
- Fan The Alarm: Use a notebook or magazine to fan the smoke alarm with fresh air. This usually shuts it off within a few seconds.
- Flip The Breaker: As a last resort, find the breaker for the smoke alarms in your electrical panel. There should be a label for it in the panel door that tells you the breaker number. CAUTION: Only flip the breaker if you are certain it’s a false alarm. Remember to turn the breaker back on or you will be unprotected.
Read Also >> How Many Electrical Fires Happen Per Year? (47 Statistics)
#2. Clean The Unit
A dirty smoke alarm from household dust, drywall debris, or insects can cause false alarms.
Spiders making cobwebs inside or around the unit is also a common false alarm culprit.
False alarms are a common experience with newly renovated properties due to paint, sanding, floor refinishing, or drywall patching. The dust floats up and into the smoke alarm, making them siren or chirp.
CAUTION: Be careful to shut off power at the breaker if you plan on removing the smoke alarm if it’s hardwired.
There are a few easy ways to clean the smoke alarm.
- Use A Damp Rag: The easiest option is to just wipe down the exterior with a damp rag. Make sure to wipe the hole in the center as well as any air ports on the side of the unit.
- Use Compressed Air: A can of compressed air is a great option to clean it. Focus on the vent holes on side and especially the center hole.
- Clean Battery Compartment & Terminals: You may also want to remove the battery cover and clean out the terminals.
#2. Relocate Or Change Type of Smoke Alarm
If you suspect the smoke alarm is tripping due to cooking fumes/smoke, steam from a bathroom, or even an HVAC vent — you can try changing or moving the alarm.
Ionization smoke alarms tend to be the most sensitive to false alarms, and you can replace it with a photoelectric style smoke alarm. You can also just try moving it do a different location. I invite you to read our detailed guide on where to place smoke detectors here.
Due to large combustion particles produced in the kitchen, garage, and utility rooms — it’s recommended to keep smoke alarms at least 20-feet away. And it’s best to keep smoke detectors at minimum 10-feet away from bathrooms, dishwashers, laundry rooms, or saunas.
If you have a smoke detector in a very cold or hot unconditioned room, the extreme temperature may be setting off the alarm as well.
#3. Change Battery
Even though a low or bad battery is typically associated with chirping rather than false alarms — changing out the battery sometimes does the trick.
A low battery or a bad battery can sometimes trigger false alarms and changing it out is possibly a fast and cheap solution.
I strongly advise looking up the manual of your smoke alarm model. Some manufacturers will specify the compatible brands of battery for your smoke alarm. If you use a cheap off-brand batteries, it will increase the chances of malfunctioning or not reaching the advertised life expectancy.
For example, the First Alert Smoke Alarm SMi100 specifies in the manual to only use:
- Duracell #MN1604
- Duracell Ultra #MX1604
- Energizer Eveready #522
- Energizer Eveready #1222
Some smoke alarms have the battery compartment on the side or front of the unit. Other units you will have to remove the smoke alarm from the bracket by turning counterclockwise. Remember to shut off power at the breaker box first since there is a shock hazard if it’s hardwired to AC power.
Do Hard Reset Before Changing Battery
Before changing the battery, I recommend doing a hard reset by taking out the old battery and disconnecting the wiring harness (if hard wired).
Remember to shut off power at electrical panel before removing the smoke alarm from the housing to avoid electrocution risk.
Once it is disconnected from all power sources, hit the test/reset button for 15 seconds to drain any residual power in the unit. Sometimes, stored electric charge in the memory or capacitor of the smoke alarm can continue triggering false alarms.
#4. Replace It
If you tried cleaning it, changing the battery, and even moving it — but it’s still giving false alarms — you may just have a faulty unit.
Smoke alarms are pretty cheap and it’s not worth spending that much energy to try and fix it. Just change it out (with ideally the same model) and see if it resolves the issue.
#5. Test The Alarm
Anytime a smoke alarm is cleaned, battery replaced, or moved — it should be tested to make sure it works.
The power LED light should show a continuous green LED light when it is operating normally.
Touch and hold the test/reset button on the cover until the alarm goes off. Press the button again (just once and quickly) to shut off the alarm. If the smoke alarms are interconnected, ALL alarms should go off at same time.
On home inspections, I like to use a can of fake smoke that can be bought online for a few bucks. You can read about it here.
8 Causes of False Smoke Alarms
1. Attic Dust
Sometimes dust and debris from an attic can trigger photoelectric smoke alarms if it’s installed on the highest level. The dust falls through the ceiling hole and into the light sensor chamber of the smoke alarm — causing a false alarm.
2. Excess Humidity
Excess humidity in the attic or interior walls can trigger false alarms. If you notice the smoke alarm going off when it is rainy outside, excess humidity may be the culprit.
If the smoke alarm is triggered by humidity on a lower level, you may need to invest in a whole house dehumidifier or moving it to a different location. Keep smoke alarms at least 10-feet away from bathrooms.
A false alarm can be set off even by just leaving a window open at night, especially for older alarms.
3. Excess Steam From Bath Or Kitchen
Steam from your bathroom or kitchen can cause false alarms. The water droplets interfere with the light chamber.
You will need to remove the smoke alarm farther away from areas with a lot of humidity — at least 10-feet from bathrooms or laundry rooms.
4. Cooking Smoke And Fumes
If your smoke alarm is too close to the kitchen, it can cause false alarms.
Air currents can also take smoke particles to a farther away location. Keep smoke detectors at least 20-feet away from kitchens, ovens, or dishwashers.
5. Dirt, Dust, and Debris
Any kind of particulates such as dust can clog the smoke alarm and interfere with the light or ionization chamber.
Renovation work that involves sanding or drywall patching can release particulates into the air and interfere with the smoke alarm. Even strong cleaning liquids may cause false alarms.
6. Insects
If you have small insects entering the smoke alarm, it can trigger false alarms. Common culprit include ants or spiders.
7. Air Drafts
If your smoke alarm is near an open window, air vent, or ceiling fan, it can trigger a false alarm. The particles in the air or just the air disturbance can trigger the light chamber and give a false alarm.
8. Electrical Interference (Noisy Power)
Smoke detectors ideally should be on a dedicated 120-volt circuit without electrical fluctuations especially from other appliances. Whether a dedicated circuit is required will depend on your local building code.
The electrical voltage changes can damage the smoke detector leading to an early demise or false alarms. Smoke alarms also shouldn’t be connected to light dimmer switches or installed near fluorescent lighting.
5-Steps To Handle A Carbon Monoxide Alarm Going Off
The average carbon monoxide alarm emits 4 loud beeps followed by a brief pause when the CO alarm goes off.
This is in contrast to a smoke alarm which emits fast and continuous beeping. This is an important distinction if you have a combo CO and smoke alarm unit.
Here are a few steps to take if your carbon monoxide alarm goes off…
#1. Open A Few Window or Doors
I recommend first opening a few windows or doors to allow in fresh air.
#2. Turn Off Alarm
I recommend first just shutting off the alarm. Similar to a smoke alarm, you can hold down the hush button on the alarm to quiet it.
Quieting the carbon monoxide alarm gives you a little room to think.
#3. Determine If Anyone Is Having Symptoms
Before leaving the home or calling emergency services, find out if anyone is having symptoms if you are unsure whether it’s a false alarm.
Common symptoms of CO poisoning include:
- Flu-like symptoms (but without fever)
- Headache
- Dizziness
- Nausea/Vomiting
- Shortness of Breath
- Fatigue
- Confusion
If anyone in your household has carbon monoxide poisoning symptoms, leave the house immediately and call emergency services.
The typical treatment for CO poisoning is giving the patient pure oxygen. Carbon monoxide gets attached to hemoglobin in the blood, so inhaling 100% pure oxygen helps to quickly reduce the CO in your red blood cells and increases oxygen to body tissues.
#4. Turn Off Gas Appliances
If nobody has symptoms, it’s likely a false alarm, but I recommend shutting off all gas-fired appliances like the furnace, stove, or water heater.
To be safe, shutting off any gas appliances temporarily until a contractor can check them out is a safe bet.
If you have an attached garage, make sure nobody accidentally left a car running which can lead to CO exposure throughout the home.
#5. Clean The Unit
A carbon monoxide alarm can be vulnerable to false alarms when the unit is dirty.
Use a can of compressed air or a vacuum brush attachment to clean the outside of the unit.
Make sure to clean all of the vent holes.
#6. Replace The Battery
A low or bad battery can also trigger false CO alarms similar to smoke alarms.
I recommend doing a hard reset before installing the new battery. This means removing the old battery and the wiring harness if hardwired.
Hold down the hush button to drain any residual power in the unit.
Also, carefully inspect the battery terminals for debris, corrosion, or damage.
2 Sample Troubleshooting Tables
X-Sense SD11
Status | LED Indicator | Audible Alarm |
Normal | Red LED flashes every 60-seconds | None |
Test | Red LED flashes rapidly | Short quick beeps |
Alarm | Red LED flashes rapidly | Short quick beeps |
Hush Mode | Red LED flashes every 5-seconds | None |
Low Battery | Red LED flashes every 60-seconds | 1 beep every 60-seconds |
Malfunction | Red LED flashes every 40-seconds | 2 beeps every 40-seconds |
First Alert SMi100
Below is a sample troubleshooting table for the First Alert SMi100. This model has two LED lights, the power and smoke LED.
Action | What You Will See & Hear |
Normal Operations | Horn: Silent; Power LED: Steady Green; Smoke LED: Off |
AC Power to Alarm is Off | Horn: Silent; Power LED: Flashes Green every minute; Smoke LED: Off |
When You Test the Alarm | Horn: Short “chirp”, then 3 beeps, pause, 3 beeps; Power LED: Green if AC power to Alarm is On, Off if Alarm is operating on battery backup; Smoke LED: Flashes Red in sync with horn |
If Battery Becomes Low (First 15 min after AC removed) | Horn: Chirps 1 time every minute; Power LED: Flashes Green 2 seconds on/2 seconds off; Smoke LED: Off |
If Battery Becomes Low (After 15 min, AC power Off) | Horn: Chirps 1 time every minute; Power LED: Flashes Green 1 time every minute; Smoke LED: Off |
Low Battery Signal is Silenced | Horn: Silent (for up to 8 hours); Power LED: Normal; Smoke LED: Off |
Alarm is Not Operating Properly (Malfunction Signal) | Horn: 3 chirps every minute; Power LED: Flashes Green 3 times every minute; Smoke LED: Off |
Alarm has reached End of Life | Horn: 5 chirps every minute; Power LED: Flashes Green 5 times every minute; Smoke LED: Off |
End of Life Signal is Silenced | Horn: Silent (for up to 2 days, 14 days total); Power LED: Steady Green (AC power) or 5 Green flashes (on battery backup); Smoke LED: Off |
Smoke is Detected | Horn: 3 beeps, pause, 3 beeps; Power LED: Steady Green if AC power to Alarm is On, Flash 1 time every minute if Alarm is operating on battery backup; Smoke LED: Flashes Red in sync with horn |
Smoke is Detected in Another Interconnected Alarm | Horn: 3 beeps, pause, 3 beeps; Power LED: Steady Green if AC power to Alarm is On, Flash 1 time every minute if Alarm is operating on battery backup; Smoke LED: Off |
Smoke Alarm is Silenced (up to 15 Minutes) | Horn: Off; Power LED: Steady Green if AC power to Alarm is On, Flash 1 time every minute if Alarm is operating on battery backup; Smoke LED: Flashes Red 3 times, pause, 3 times |
Final Thoughts
Smoke alarm chirps and false alarms can be an annoying problem.
The most common reason for chirping is a low battery but a dirty smoke alarm can also activate annoying beeps.
False alarms can also be related to battery problems but a dirty unit tends to be more common. Things like drywall dust or even spider cobwebs can clog the vent holes and activate the alarm.
I hope you enjoyed this guide by TimberSill. Ask me any questions below or share your experience dealing with faulty smoke alarms.