Furnace makes loud banging or booming noises at startup (delayed ignition).
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: Turn off gas and power immediately. Delayed ignition can damage the furnace and flue.
Steps (for technician or advanced user only):
- Inspect burner: Remove and clean the burner assembly, ensuring all ports are free of rust and debris.
- Check electrode position: Verify the ignition electrode is positioned and gapped according to Cointra specifications so that the spark occurs directly in the gas stream.
Professional service: A licensed technician must check gas pressure, combustion, and adjust or replace components as needed. Do not continue operating the furnace with banging at startup.
Repair Difficulty
Required Part
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