Alarm memory · FireAngel · carbon monoxide
FireAngel: CO alarm flashing red every 20 seconds, silent
Alarm memory: the CO alarm has been activated recently, possibly while nobody was home (FA3313 and FA3820).
- What you see
- One red flash about every 20 seconds
- What you hear
- Silent
If it is sounding a full alarm instead: the maker’s emergency instruction
Carbon monoxide alarm
FireAngel: if the CO alarm goes off with four loud beeps, immediately open doors and windows, stop using any appliances and switch them off, and leave the building taking the CO alarm with you. If it stops after 10 minutes in fresh air, you may have a CO leak: call your gas supplier or the national gas emergency line on 0800 111 999 and wait for instructions. Do not go back in until it has been declared safe.
From Why is my FireAngel CO alarm beeping and flashing? and Fire & Smoke Alarm FAQs.
Smoke alarm
FireAngel: never ignore any alarm. If your smoke or heat alarm goes off and you are not absolutely certain of the source, get everyone out of the house immediately — sleeping children first — and call the fire and rescue service without delay, however small the fire (FireAngel’s FAQ: evacuate immediately and call 999).
From FA6611, FA6615 & FA6620 Optical Smoke Alarm & FA6720 Heat Alarm — User Manual and Fire & Smoke Alarm FAQs.
What FireAngel says to do about this signal
- FireAngel’s support page names the signal without a separate step. Its FA3820 FAQ says the 30-day memory is there so you can check whether CO was detected while you were away — and if it was, FireAngel’s CO instruction (above) is what it says to do about CO.
From Why is my FireAngel CO alarm beeping and flashing? and Fire & Smoke Alarm FAQs. If your alarm’s pattern is not exactly this, check the manual for your model: FireAngel models do not all use the same signals.
Other FireAngel signals
Sources
Every line on this page comes from FireAngel’s own documents, read on the date shown. Nothing is taken from third-party code sites or other makes.
- FireAngel Safety Technology: Why is my FireAngel CO alarm beeping and flashing? — FA3313 and FA3820 CO alarms (support article). www.fireangel.co.uk Checked 2026-09-29.
- FireAngel Safety Technology: Fire & Smoke Alarm FAQs — FA6615-R, FA6620-R, FA6829S, FA3820-EUX10 (FAQ entries). www.fireangel.co.uk Checked 2026-09-29.
- FireAngel Safety Technology: FA6611, FA6615 & FA6620 Optical Smoke Alarm & FA6720 Heat Alarm — User Manual — FA6611, FA6615, FA6620, FA6720 (document GN5914R3). www.fireangel.co.uk Checked 2026-09-29.