BoilerFaultCodesTechnical description
DHW mode: Fan overrun
What causes this fault?
This fault occurs when the boiler's control system detects that the fan is spinning but sending back incorrect signals, or it isn't spinning at the speed required for safe combustion. The most common reason is an internal electrical failure within the fan motor itself or a communication glitch between the fan and the main circuit board. Without the fan functioning perfectly to clear exhaust gases, the boiler shuts down as a safety precaution.
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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