FireAngel alarm signals: beeps, chirps and lights
FireAngel’s FA6611, FA6615 and FA6620 smoke alarms (and the FA6720 heat alarm) count their warnings on a 40-second beat: one beep, a double beep or a triple beep, each with the same number of red flashes. Its CO alarms use four loud beeps for an alarm and a slower red flash for alarm memory.
If it is sounding a full alarm: the maker’s emergency instruction
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.
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.
Every FireAngel signal we could source
| What you see | What you hear | What it means |
|---|---|---|
| One red flash about every 40 seconds | Silent | Normal operation: Normal operation: after activation the red LED flashes about once every 40 seconds to show the alarm is active. |
| One red flash about every second | Full alarm, loud and continuous | Real alarm: Smoke (or, on the FA6720, heat) has been detected. |
| One red flash about every second | Silent | Hush or silence mode: Silence mode after a known false alarm: the alarm is quiet for 10 minutes, the LED keeps flashing once a second, and it returns to full sensitivity by itself. |
| One red flash about every 40 seconds | One chirp about every 40 seconds | Low battery: Low battery. |
| Two red flashes about every 40 seconds | Two chirps about every 40 seconds | Fault: Fault: FireAngel says the alarm may not signal an alert. |
| Three red flashes about every 40 seconds | Three chirps about every 40 seconds | End of life: End of life: FireAngel says the alarm may not signal an alert. |
| Red light | Full alarm, four beeps then a pause, repeating | Real alarm: Carbon monoxide has been detected. |
| One red flash about every 20 seconds | Silent | Alarm memory: Alarm memory: the CO alarm has been activated recently, possibly while nobody was home (FA3313 and FA3820). |
| Three yellow or amber flashes about every 60 seconds | Three chirps about every 60 seconds | End of life: End of life on the FA6829S CO alarm: its 10-year sensor and battery are used up. |
Sources
FireAngel’s own documents only, read on the date shown.
- 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.
- 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: Why is my FireAngel smoke alarm beeping? — FireAngel smoke and heat alarms (support article). www.fireangel.co.uk Checked 2026-09-29.