Boiler displays A15, burner stops, may be associated with very high system temperature readings.

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

Failed overheat thermostat, NTC sensors reading incorrectly high, PCB misinterpreting sensor data, Severe circulation issues

Safety: Allow the boiler to cool completely. Do not bypass any safety devices.

Check pressure and bleed: Ensure system pressure is correct and bleed radiators to remove air.
Technician – test overheat thermostat: Check continuity and trip temperature of the Beretta high limit thermostat. Replace if faulty.
Technician – verify NTC readings: Compare flow and return NTC values to actual pipe temperatures. Replace sensors if readings are inaccurate.
Investigate circulation: Confirm pump operation and check for blocked valves or filters.

Hard 4/5

Overheat Thermostat

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