Carbon Monoxide & Your Furnace: Critical Safety Guide for Utah Homeowners

Carbon monoxide (CO) is often called the "silent killer" — colorless, odorless, and lethal at concentrations above 400 parts per million. Your gas furnace is the most common source of CO in residential homes. Every HVAC Coalville technician checks for CO risk on every heating service call, because we know it saves lives.

How Furnaces Produce Carbon Monoxide

A properly functioning gas furnace burns natural gas completely, producing carbon dioxide (CO2) and water vapor — both harmless in normal ventilation. CO is produced when combustion is incomplete, which happens when:

• The heat exchanger is cracked or corroded
• The burner is dirty and flame pattern is distorted
• The flue pipe is blocked, disconnected, or improperly sloped
• There is insufficient combustion air supply
• The system is over-fired (too much gas pressure)

The Heat Exchanger Risk

The heat exchanger is a thin metal chamber that separates combustion gases from your home's air supply. Over time — typically 15-25 years — thermal cycling causes metal fatigue and cracking. When the heat exchanger cracks, combustion gases (including CO) can mix with the air your blower circulates throughout your home.

A cracked heat exchanger cannot be repaired. The furnace must be replaced immediately and should not be operated until replacement is complete.

Warning Signs of CO Exposure

• Headaches that improve when you leave the house
• Nausea, dizziness, or confusion among family members simultaneously
• Pets acting lethargic or ill
• Yellow or orange furnace flame (should be blue)
• Excess moisture on windows during furnace operation
• CO detector alarm

What to Do If Your CO Detector Alarms

Immediately evacuate all people and pets. Do not stop to grab belongings. Call 911 from outside. Do not re-enter until emergency responders confirm it is safe. Then call HVAC Coalville for emergency heating service at (435) 244-1090.

Prevention

Annual furnace maintenance is the most effective prevention. Our technicians use combustion analyzers and visual inspection tools — including flexible cameras — to inspect heat exchangers and combustion quality on every tune-up. We also recommend hardwired CO detectors with battery backup on every floor, placed according to manufacturer guidelines.