De Dietrich Combustion Resonance / Gas Flow Noise

Furnace emits a high-pitched whistling or howling noise during operation

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

Incorrect gas valve adjustment on De Dietrich burner, Flue resonance due to length or termination, Partially blocked burner head, Fan speed not matched to gas rate

How to Fix / Troubleshooting

Critical safety: Combustion adjustments must only be made by a qualified gas technician with a flue gas analyser.

User actions:

Note conditions: Record when the noise occurs (low or high power, DHW or heating) to inform the technician.
Check flue terminal: Ensure the terminal is not partially blocked or modified.

Professional help: A technician should check combustion settings, burner cleanliness, and flue configuration.

Repair Difficulty

Professional Required 5/5

Required Part

Premix Burner Assembly

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