Wolf Heat Exchanger Kettling / Localised Boiling

Boiler makes loud banging or knocking noises (kettling) during operation

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

Limescale build-up in primary heat exchanger, Sludge in system water, Insufficient flow rate through boiler, Incorrect pump setting

Safety: Noisy kettling can indicate overheating. Do not ignore persistent loud noises.

Check system pressure and flow: Ensure pressure is correct and enough radiators are open to allow flow.
Bleed air: Remove trapped air from radiators and high points.
Adjust pump speed: If the pump is set too low, increase to the recommended setting.
System cleaning (technician): A professional should power-flush or chemically clean the system and, if necessary, descale or replace the primary heat exchanger.

Hard 4/5

Primary Heat Exchanger

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