BoilerFaultCodesPotterton H00266 Fault Code
The Potterton H00266 fault code means: your boiler's computer brain has encountered a communication error or internal failure related to how it monitors system pressure.. It appears on 1 Potterton model in our database.
Technical description: Boiler Control Assembly (Use with ‘Huba’pressure transmitter only)
What causes the Potterton H00266 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 fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Potterton models that show the H00266 fault code
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Source
Potterton H00266 fault code information on this page is sourced and cross-checked against the official Potterton service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026