BoilerFaultCodesYour boiler's fan is not spinning fast enough to safely clear away exhaust fumes, so the system has shut down as a precaution.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Fan speed too low
What causes this fault?
This fault occurs when the boiler's internal computer detects that the fan is not reaching the required speed to safely expel waste gases through the flue. The most common reasons include a buildup of dirt or debris on the fan blades, a failing motor, or a blockage within the small tubes that measure air pressure.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like C1 — no call-out fees, no surprises.
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