BoilerFaultCodesTechnical description
Heating system fan over run
What causes this fault?
This fault occurs when the boiler's control board fails to receive a signal that the fan has slowed down or stopped after a heating cycle, causing it to stay in a permanent cooling mode. The most common reason is a malfunctioning relay on the main circuit board or a faulty fan that is sending incorrect speed data back to the system. While the boiler is stuck in this 'over run' phase, it will refuse to ignite for central heating or hot water because it believes it hasn't finished cooling down.
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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