Display shows E6; unit may not modulate correctly or may shut down under load.
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. Do not run the heater with a suspected fan fault—risk of improper combustion.
Check airflow path:
- Inspect intake: Ensure the combustion air intake (on concentric vent or separate intake) is not blocked by debris, snow, or insects.
- Listen for fan operation: Restore power, open a hot tap, and listen for the fan starting. If it does not run at all, proceed to internal checks.
- Inspect fan wiring: Remove the front cover. Locate the combustion fan near the top of the unit. Check that its connector is firmly attached to the control board and that wires are intact.
- Check for obstructions: Spin the fan blades gently by hand (with power OFF). They should rotate freely without scraping. Remove any visible debris.
- Replace fan if defective: If the fan is seized, noisy, or not receiving power (requires meter), replace the combustion fan motor assembly.
When to call a technician: For fan replacement, control board diagnosis, or any combustion-related work.
Repair Difficulty
Required Part
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