Furnace makes loud banging or booming noise at startup when burners ignite.
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
Danger: Delayed ignition can damage the furnace and pose a safety risk. Do not repeatedly cycle the furnace.
- 1. Shut down furnace: Turn off power and gas to prevent further operation.
- 2. Visual inspection: Through the burner access, look for heavy rust or debris on burners.
Burner cleaning, alignment, and gas pressure adjustment must be done by a qualified HVAC technician familiar with Lennox furnaces.
Repair Difficulty
Required Part
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