Real alarm · Aico · smoke
Aico: Full alarm sound, red light flashing rapidly
Fire sensed. The alarm that sensed the smoke flashes its red light rapidly (about every half second); interconnected alarms sound too but do not flash that way.
- What you see
- One red flash about every half a second
- What you hear
- Full alarm, loud and continuous
Do this first: the maker’s emergency instruction
Smoke alarm
Aico: if the alarms are sounding there may be a fire — evacuate, and if in doubt always assume the fire is real (homeowner FAQ). The Ei650 leaflet: check doors for heat before opening, crawl low under heavy smoke, get out and meet at your prearranged place, call the Fire Brigade from a neighbour’s house or a mobile phone giving your name and address, and never re-enter a burning house.
From Homeowner FAQs — Why is my alarm beeping? and Battery Powered Smoke Alarms Ei650 Series — instruction leaflet (Rev 6).
Carbon monoxide alarm
Aico: a sounding CO alarm means carbon monoxide is likely to be present. Turn off any gas appliances, open windows and doors, and leave the property; ring the emergency number of your gas or fuel supplier; do not go back in until the alarm has stopped.
From Homeowner FAQs — Why is my alarm beeping? and Basic Alarm Fault Finding.
What Aico says to do about this signal
- Get out first (above). Only when you are sure there is no fire: find the alarm with the rapidly flashing red light and press its Test/Hush button; if that does not silence it, Aico says to clean the alarm with a vacuum and wait 10 minutes.
From Battery Powered Smoke Alarms Ei650 Series — instruction leaflet (Rev 6) and Homeowner FAQs — Why is my alarm beeping?. If your alarm’s pattern is not exactly this, check the manual for your model: Aico models do not all use the same signals.
Other Aico signals
Real alarm on other brands
The same state sounds and looks different on each make — which is why a chirp pattern cannot be read without the brand.
Sources
Every line on this page comes from Aico’s own documents, read on the date shown. Nothing is taken from third-party code sites or other makes.
- Aico / Ei Electronics: Battery Powered Smoke Alarms Ei650 Series — instruction leaflet (Rev 6) — Ei650, Ei650C, Ei650W, Ei650i. www.aico.co.uk Checked 2026-09-29.
- Aico: Homeowner FAQs — Why is my alarm beeping? — Aico mains and CO alarms, incl. 140RC series (FAQ). www.aico.co.uk Checked 2026-09-29.
- Aico: Basic Alarm Fault Finding — Aico alarms (trade fault-finding page). www.aico.co.uk Checked 2026-09-29.