Safety Concern
Furnace Has a Yellow Flame?
A yellow or orange flame indicates incomplete combustion—a potential carbon monoxide hazard that requires immediate attention.
Get Immediate HelpCarbon Monoxide Warning
A yellow flame can indicate carbon monoxide production. If you also experience headaches, dizziness, or nausea, leave your home immediately and call 911. CO is colorless and odorless—a yellow flame is your visual warning sign.
- Ensure you have working CO detectors
- Open windows for ventilation
- Schedule immediate professional inspection
- Do not attempt DIY repairs
What Causes a Yellow Flame
Dirty Burners
UrgentDust and debris on burners disrupts proper gas-air mixture.
Required: Professional burner cleaning required.
Incorrect Gas Pressure
UrgentToo much or too little gas affects combustion.
Required: Professional gas pressure adjustment.
Clogged Air Intake
UrgentInsufficient air for complete combustion.
Required: Professional inspection and cleaning of air intake.
Cracked Heat Exchanger
CriticalAllows combustion gases to mix with household air.
Required: Immediate professional inspection. May require furnace replacement.
Improper Venting
UrgentExhaust not properly venting, affecting combustion.
Required: Professional inspection of flue and venting system.
Important Guidelines
- Immediately—yellow flame is always a professional service issue
- Never attempt to adjust burners yourself
- If accompanied by any symptoms of CO exposure, call 911 first
Related Safety Resources
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