Carbon monoxide safety

Where CO comes from

Any appliance that burns fuel can produce carbon monoxide when combustion is incomplete or venting fails:

• Furnaces and wall heaters.
• Gas water heaters.
• Gas ranges and ovens.
• Fireplaces and gas log sets.
• Gas dryers.
• Cars, generators and gas tools in attached garages.

California requirements

Homes with a fossil-fuel burning appliance, a fireplace or an attached garage must have CO alarms approved by the State Fire Marshal. Sellers must disclose compliance in the Transfer Disclosure Statement, and landlords must install alarms in rental units.

Placement, based on manufacturer instructions and the California building code:

• Outside each separate sleeping area, in the immediate vicinity of the bedrooms.
• On every level of the home, including basements.
• Inside bedrooms where a fuel-burning appliance is located in the bedroom or its bathroom (newer construction).

What the inspector checks

1. CO alarms are present in the required locations.
2. Gas appliances have proper venting with correct slope and secure connections.
3. Combustion air is available for furnaces and water heaters in closets.
4. Flame appearance and signs of rollout or scorching.
5. The garage-to-house door seals and closes, keeping exhaust out.

Inspectors don’t usually test for CO levels with instruments as part of a standard inspection, though some carry a CO detector as a precaution.

Maintenance

Test alarms monthly, replace batteries as directed, and replace the alarm itself at the end of its listed life, which is often 7 to 10 years. Have gas appliances serviced regularly, and never run a generator or car in an attached garage.