Boiler displays F41, burner output limited or boiler shuts down under load

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

Pump running at too low speed, Partial blockage in primary circuit, Air in system, Incorrectly balanced heating system

Safety: Turn off power and allow the system to cool.

Steps:

Bleed air from radiators and the boiler’s air vent.
Check and, if possible, increase the pump speed setting within Protherm guidelines.
Ensure all valves are open and that thermostatic radiator valves are not all closed simultaneously.
Clean system filters and consider system flushing if sludge is suspected.

After repair: Reset the boiler and monitor temperature rise to ensure F41 does not recur.

Medium 3/5

Circulation Pump

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