Gas furnaces are safe when properly maintained, but they involve combustion and require attention to safety. Here are essential practices for safe operation.
Carbon Monoxide Protection
Carbon monoxide (CO) is a colorless, odorless gas produced by combustion. Furnaces normally vent CO safely outside, but malfunctions can allow it indoors.
Install CO detectors on every level of your home and near sleeping areas. Test monthly and replace batteries annually. Replace detectors every 5-7 years.
Know the symptoms: Headache, dizziness, nausea, confusion. If multiple family members feel ill and symptoms improve when leaving home, suspect CO exposure.
If CO detector alarms: Leave immediately. Call 911 if anyone has symptoms. Do not re-enter until cleared by professionals.
Heat Exchanger Safety
The heat exchanger separates combustion gases from circulated air. Cracks allow combustion products including CO to enter your home.
Annual inspection by a professional catches heat exchanger problems. This is the most important furnace safety check.
Warning signs include rust, cracks, soot buildup, or yellow/flickering flame. Any of these warrant immediate professional inspection.
Gas Safety
Know the smell. Natural gas is odorized to smell like rotten eggs. Any gas odor needs immediate attention.
If you smell gas strongly: Leave immediately without using light switches or anything that could create a spark. Call your gas utility from outside.
Know your shutoff. Locate the gas shutoff valve for your furnace and for your whole house. Know how to turn it off if needed.
Combustion Air
Furnaces need adequate air for proper combustion. Never block vents or close off the furnace room. Do not store items near the furnace that could restrict airflow.
Area Around the Furnace
Keep clear. Maintain clearances specified by the manufacturer. Never store flammable materials near the furnace.
No storage. The furnace room is not a storage closet. Clutter creates fire risk and restricts maintenance access.
Filter Maintenance
Clogged filters can cause overheating, triggering safety shutoffs or in extreme cases creating fire risk. Regular filter maintenance is a safety practice, not just efficiency.
Professional Maintenance
Annual professional maintenance includes safety checks beyond DIY capability: - Heat exchanger inspection - Gas pressure verification - Combustion analysis - Safety control testing - Vent inspection
Do not skip professional maintenance on gas furnaces.
When to Call for Help
Seek professional help immediately for: - Gas odor - CO detector alerts - Visible damage or rust - Soot around unit - Yellow or flickering flame - Repeated safety shutdowns
Safety issues are not DIY projects. Professional diagnosis protects your family.