BoilerFaultCodesTechnical description
Gas family check unsuccessful
What causes this fault?
This fault occurs when the boiler's internal computer tries to verify the quality and type of gas entering the system but fails to receive a stable reading. It is physically caused by a mismatch between the gas valve's output and the detection signal from the ignition probes, often due to a components failing to regulate the fuel flow correctly. The most common reason is a malfunctioning gas valve or a faulty control board that can no longer process the flame signal.
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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