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Why is my FireAngel CO alarm beeping and flashing?

CO Safety

27 August 2024

Last Updated: 16 February 2026

If your FireAngel carbon monoxide (CO) alarm is beeping, you may have a possible CO leak. Follow our troubleshooting advice to find out more.

FireAngel’s new range of carbon monoxide alarms are packed full of cutting-edge safety features and use intelligent sensing technology for a rapid reaction to rising levels of CO.

However, if your CO alarm is beeping, flashing red or not responding during a test, follow our troubleshooting guide to decipher the cause. This guide applies to FireAngel FA3313 and FA3820 alarms.

Why is my FireAngel CO alarm beeping?

Alarm icon flashes red for 4 seconds, indicating a CO alarm beeping memory notification.

If your CO alarm is beeping once, twice or three times regularly, you may need to replace your alarm batteries, or you could be experiencing exposure to low levels of CO. The guide below will help to identify the cause of beeping.

 

Why is my FireAngel CO alarm going off?

Four-step safety guide: if CO alarm beeping, ventilate, evacuate, then call for support.

If your FireAngel CO alarm is going off fully, and you can hear 4 loud beeps, immediately open any doors or windows in your home, stop using any appliances, switch them off and evacuate the building taking the CO alarm with you.

If your CO alarm stopped beeping after being outside in the fresh air for 10 minutes, you may have a possible carbon monoxide leak in your home. We recommend calling your gas supplier or national emergency gas helpline on 0800 111 999 and await further instruction.

Carbon monoxide is a highly poisonous gas, caused by fuel not burning properly. It cannot be seen, smelt or tasted by the human senses and is only detectable through a CO alarm.

If your CO alarm did not stop beeping after being outside in the fresh air for 10 minutes and it is still within warranty, please contact our Customer Support team. If it is not within warranty, please replace your alarm as soon as possible.

Why is my FireAngel carbon monoxide alarm flashing a red light?

If your CO alarm is flashing a red LED light every 20 seconds, it has been activated recently. This is referred to as ‘alarm memory’, find out more about what this feature means here.

Why does my FireAngel CO alarm not sound when I press the test button?

Four steps to test your device and address issues like a CO alarm beeping—call support if needed.

If your FireAngel carbon monoxide alarm is new and the test button is not working, try removing the isolation pin. Once removed, wait for at least 1 minute for alarm to initiate. If the alarm now sounds once test button is pressed your alarm is working correctly. If it still does not sound, please get in touch with our Customer Support team.

However, if you have had your FireAngel carbon monoxide alarm for a few years, but it is still within warranty, and the isolation pin has been removed, please get in touch with our Customer Support team.

If it is not within warranty, please replace your alarm as soon as possible.

 

Got a burning question? Get in touch

If you can't find what your looking for on our blogs and looking for further guidance and advice, our UK-based Customer Support team are on hand all week from 8:30am until 5:30pm, they can answer any further queries you may have on our products, solutions or services.