Carbon Monoxide Detector Beep

You may want to ask this question when carbon monoxide detector beeping. What should I do? Before I answer this question, I want to tell you something. Please always bear in mind that whenever you find carbon monoxide detector beeping always treat it as actual carbon monoxide detection.

Never treat it as carbon monoxide alarm low battery, malfunction or it already reaches its end of life. If you think that way, you and your family members may be injured or killed.

Please remember that you should be able to distinguish between “beep” and “chirp” sounds in this case. Do not think that they have same meaning.

Watch the video guide below to understand when the unit beeping or chirping.

This guides is made for First Alert carbon monoxide detector especially Model CO600. For the other models from First Alert and other makers will be provided in different articles.

Carbon Monoxide Detector Beeping – Steps to Do

Carbon monoxide detector beeping occurs when you push the test/silence button or it sensor detects carbon monoxide at an alarm level. At the same time, its power/alarm light flashes quickly. When you hear it is beeping and you do not touch the test/silence button, then you should take action immediately.

carbon monoxide alarm beeping
Before describing what you have to do, it is important to make this clear. Here is how the First Alert carbon monoxide detector acts when you press test/silence button or it detects carbon monoxide at alarm level.

When you push the test/silence button:
Horn sounds loudly 4 beeps – pause – 4 beeps – pause.
Power/alarm light flashes quickly.

When it detects carbon monoxide at alarm level:
Horn sounds loudly 4 beeps – pause – 4 beeps – pause. This continues until the gas level returns to normal.
Power/alarm light flashes quickly. The light will shine continuously if the gas level returns to normal.

Follow the steps below if you find the detector beeping due to existence of carbon monoxide:

  1. Push the test/silence button.
  2. Phone nearest emergency service in your town, fire department or 911.
  3. Immediately move to fresh air. You can do this by opening window or door. Do not panic but try to speed your steps.
  4. Make sure your family members and guests are already with you.
  5. Do not re-enter to the location where carbon monoxide detector beeping. Stay at the fresh air until emergency service arrives at your home.
  6. After the detector stop beeping, call qualified appliance technician to investigate the source of CO. Repair or replace immediately appliance that is found to be the source of CO after investigation finished.

Remember that failure to do these steps, you or your family members can be killed. When it is beeping or the alarm sounds, you must not disregard it.

Understand the Difference between Carbon Monoxide Detector Beeping and Chirping

Once again, I would to remind you that you should be able to distinguish between beeping and chirping. First Alert’s carbon monoxide detector chirping whenever it is malfunction or has reached its end of life.

If the detector is malfunction, then the following indications appear:

Horn sounds 3 chirps every minute.
Power/alarm light flashes 3 times approximately once a minute.

If the detector has reached its end of life:

Horn sounds 5 chirps every minute.
Power/alarm light flashes 5 times approximately once a minute.

If you feel hard to distinguish between those two indications, do not worry. Because every time you find both indications, you should replace the unit immediately. Yes, you should. This tells you that your carbon monoxide detector has failed to work. You need a new one.


If you find your carbon monoxide detector beeping, take action immediately. Failure to do so will result an injury or death. And I strongly recommend you to put a slogan in your home to announce this to everyone in your home.

Incoming search terms: