BoilerFaultCodesYour boiler is trying to heat your water, but the internal fan responsible for safety cannot get started.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: DHW mode fan start up error
What causes this fault?
This fault occurs when the boiler's control board sends a signal to the fan to begin spinning, but the fan fails to respond or reach the required speed. The most common reasons are a physical blockage in the fan's blades, a loose internal electrical connection, or a failure in the fan's motor and electronics.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like S.11 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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