Furnace Has a Yellow Flame?
A yellow or orange flame indicates incomplete combustion—a potential carbon monoxide hazard that requires immediate attention.
Get Immediate Help (516) 259-1191Carbon 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.
Incorrect Gas Pressure
UrgentToo much or too little gas affects combustion.
Clogged Air Intake
UrgentInsufficient air for complete combustion.
Cracked Heat Exchanger
CriticalAllows combustion gases to mix with household air.
Improper Venting
UrgentExhaust not properly venting, affecting combustion.
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
Diagnostic Visit — $199
An EPA-certified technician inspects your system, identifies the issue, and applies the $199 fee toward any approved repair.
Related Safety Resources
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