High Lockout
H00266 on Potterton Powermax HE

Your boiler's computer brain has encountered a communication error or internal failure related to how it monitors system pressure.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Boiler Control Assembly (Use with ‘Huba’pressure transmitter only)

What causes this fault?

This fault occurs when the boiler's main control board loses communication with the digital pressure sensor or detects an internal electronic failure. It is often caused by a malfunctioning circuit board that can no longer process signals correctly, or a sensor that has failed and is sending unreadable data. Essentially, the boiler shuts down because it can no longer safely verify if there is enough water pressure to operate.

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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