BoilerFaultCodesTechnical description
Shut-off mode
What causes this fault?
This fault occurs when the boiler's internal sensors detect that the water temperature is rising too quickly or has exceeded safe operating limits. This is usually caused by a lack of water flow through the heat exchanger, often due to a pump failure or a blockage in the system pipework. To prevent components from warping or melting, the boiler shuts down until the temperature drops back to a safe level.
This issue often surfaces during the first cold spell of autumn when the heating is turned on after a long summer break, as internal pumps can seize during periods of inactivity.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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