Protherm Kettling / Boiling in Heat Exchanger

Water heater makes loud banging or knocking noises when heating

Advertisements

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.

Advertisements

Possible Causes

Heavy limescale buildup in heat exchanger, Restricted water flow, Incorrect gas rate causing localized overheating, Air pockets in primary circuit

How to Fix / Troubleshooting

Safety first: Turn off power and gas. Allow the unit to cool before touching the heat exchanger or pipes.

  • Check water flow: Ensure inlet filters are clean and valves fully open.
  • Bleed air: Remove air from the system using bleed valves and automatic vents.
  • Descale heat exchanger: Perform a chemical descaling of the primary or plate heat exchanger using a pump and approved descaler.
  • Gas rate check: Have a technician verify and adjust burner gas rate to Protherm specifications.

Warning: Persistent kettling can damage the heat exchanger and increase energy consumption; do not ignore it.

Advertisements

Repair Difficulty

Medium 3/5

Required Part

Primary Heat Exchanger
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements