Emergency
The CO alarm is going off.
Carbon monoxide has no colour, no smell and no taste. The alarm is the only warning you get, so treat it as real.
First
Get to fresh air.
Then call 911, or your local fire department.
Do this now
Fresh air first. Then call 911.
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Press Test/Reset, then get out
Press the button on the alarm, and move everyone outside or to an open door or window straight away.
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Call 911
Or your local fire department.
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Stay out until the all clear
Don't go back in until emergency services have come, the house has been aired out and the fire department says it's clear.
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If it goes off again
Kidde says to repeat these steps and call a qualified appliance technician to find the source.
Source: Kidde, What Should I Do When My Carbon Monoxide Alarm Sounds?, checked 2026-10-22.
Don't
- Ignore it, or wait to see if it stops.
- Brush off a number on a digital alarm's screen: Kidde says to assume it senses carbon monoxide, sound or no sound.
- Keep using a gas appliance you suspect. If it's safe to, PG&E says turn it off and open the windows.
Source: PG&E, Carbon Monoxide Safety, checked 2026-10-22.
After the all clear
Find the source before it runs again
If the suspect is your gas furnace, book a furnace repair and tell us the alarm went off.
PG&E advises having every heating system and fuel-burning appliance inspected by a qualified professional once a year.
California law requires a CO alarm in every home with a gas appliance, a fireplace or an attached garage.
Book a furnace repairFurnace maintenance
Source: California Health and Safety Code, section 17926, checked 2026-10-22.
Tell us what it's doing. We'll take it from there.
Call and describe the problem: the noise, the smell, the room that never warms up. Or book a visit online.
