Boiler’s gas burner flame appears yellow and lazy instead of blue and stable.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: Turn off power and gas. Yellow flames can indicate carbon monoxide production; ensure adequate ventilation and install CO detectors.
- Step 1 – Check air intake: Make sure the combustion air intake is not blocked or restricted.
- Step 2 – Inspect burner: Remove and clean the burner as per the Bradford White manual. Remove dust, lint, and rust with a soft brush and vacuum.
- Step 3 – Gas pressure and orifices (pro): A technician should verify gas pressure and confirm that the correct orifices are installed for the fuel type (natural gas vs. LP).
- Step 4 – Heat exchanger inspection (pro): Blocked passages can alter airflow and flame shape. Have a professional inspect and clean the heat exchanger.
- Step 5 – Combustion analysis (pro): Perform a combustion test to ensure CO and O2 levels are within safe limits.
Warning: Do not continue to operate the boiler with yellow flames; call a qualified gas technician.
Repair Difficulty
Required Part
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