Safety
Carbon Monoxide and Your Furnace: Safety Guide for Homeowners
February 3, 2022•6 min read
Carbon monoxide (CO) is called the "silent killer" because it's colorless and odorless. If you have a gas furnace, understanding CO risks is essential for your family's safety.
How Furnaces Can Produce CO
All gas furnaces produce some carbon monoxide during combustion. Normally, this is safely vented outside. Problems occur when:
- The heat exchanger develops cracks
- Venting is blocked or damaged
- Combustion is incomplete (dirty burners, wrong gas pressure)
- The furnace backdrafts
All gas furnaces produce some carbon monoxide during combustion. Normally, this is safely vented outside. Problems occur when:
- The heat exchanger develops cracks
- Venting is blocked or damaged
- Combustion is incomplete (dirty burners, wrong gas pressure)
- The furnace backdrafts
Warning Signs of CO Problems
Watch for these indicators:
- Yellow or flickering burner flame (should be blue)
- Soot around the furnace
- Excess moisture on windows when furnace runs
- Rust on vent pipes
- Family members experiencing headaches, nausea, or dizziness
If you notice any of these, ventilate your home and call for furnace repair immediately.
Watch for these indicators:
- Yellow or flickering burner flame (should be blue)
- Soot around the furnace
- Excess moisture on windows when furnace runs
- Rust on vent pipes
- Family members experiencing headaches, nausea, or dizziness
If you notice any of these, ventilate your home and call for furnace repair immediately.
CO Detector Requirements
California law requires CO detectors:
- On every level of the home
- Near sleeping areas
- Tested monthly
- Batteries replaced annually
- Units replaced every 5-7 years
California law requires CO detectors:
- On every level of the home
- Near sleeping areas
- Tested monthly
- Batteries replaced annually
- Units replaced every 5-7 years
Prevention Through Maintenance
Annual professional maintenance is your best protection:
- Heat exchanger inspection (most critical)
- Combustion analysis
- Venting verification
- Safety control testing
See our complete furnace maintenance checklist for what technicians check.
Annual professional maintenance is your best protection:
- Heat exchanger inspection (most critical)
- Combustion analysis
- Venting verification
- Safety control testing
See our complete furnace maintenance checklist for what technicians check.
If Your CO Detector Alarms
1. Get everyone out of the house immediately
2. Call 911 from outside
3. Don't re-enter until cleared by emergency responders
4. Have your furnace inspected before using again
Never ignore a CO alarm. Even if it seems like a false alarm, have it investigated.
1. Get everyone out of the house immediately
2. Call 911 from outside
3. Don't re-enter until cleared by emergency responders
4. Have your furnace inspected before using again
Never ignore a CO alarm. Even if it seems like a false alarm, have it investigated.
When to Call for Service
- Any suspected CO issue
- Yellow burner flame
- Furnace soot or rust
- Unusual smells when furnace runs
- Family experiencing symptoms
For emergencies, call our emergency HVAC service.
- Any suspected CO issue
- Yellow burner flame
- Furnace soot or rust
- Unusual smells when furnace runs
- Family experiencing symptoms
For emergencies, call our emergency HVAC service.
The Bay Area Factor
Our relatively mild winters mean furnaces run less often, which can actually mask problems. When we do have cold snaps, furnaces that haven't been checked may pose increased risk. Schedule maintenance before heating season begins.
Our relatively mild winters mean furnaces run less often, which can actually mask problems. When we do have cold snaps, furnaces that haven't been checked may pose increased risk. Schedule maintenance before heating season begins.