Reset Memory: Hold down the test button until the red light stops and the green
light starts flashing. Cover the horn with a cloth to muffle the alarm during this time.
Please note that the memory will also be reset when the CO Alarm is switched off.
3. Where to place CO Alarms
3.1 Ideally a Carbon Monoxide Alarm should be installed in:
- Every room containing a fuel burning appliance, and
- Remote rooms where occupants spend a considerable amount of time
- Every bedroom
However if the number of Carbon Monoxide Alarms to be fitted is limited, the
following points should be considered when deciding where best to fit the alarm(s)
- If there is an appliance in a room where people sleep, place a CO Alarm in
this room
- Locate a CO Alarm in a room containing a flueless or open-flued appliance, and
- Locate an Alarm in a room where the occupant(s) spend most of their time (e.g.
sitting room)
Table C: CO Alarm Memory Indicators
CO Gas Level
ppm > 43 ppm
2 flashes every minute (approx)
ppm > 80 ppm
4 flashes every minute (approx)
ppm > 150 ppm
8 flashes every minute (approx)
Red Light Response
24 Hours
On Demand (Button Press)
2 flashes
4 flashes
8 flashes