BoilerFaultCodesTechnical description
A blockage in the appliance is affecting the system’s pressure.
What causes this fault?
This fault occurs when the internal pressure sensor detects a sudden drop or spike caused by a lack of water movement. It is usually triggered by a physical blockage in one of the heat exchangers or a failing pump that can no longer push water through the narrow internal pipework. This effectively chokes the system, causing the boiler to shut down to prevent overheating.
This issue often surfaces in autumn when the heating is turned back on after summer, as settled debris in the system is suddenly shifted into the boiler’s narrow components.
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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