BoilerFaultCodesWhat the manual says
Manufacturer manualFan speed too low. Fan harness and connections.
Shared across the range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
What causes this fault?
This fault occurs when the boiler's control system detects that the fan is not rotating at the required speed to safely expel exhaust gases. The most common reasons are a build-up of debris within the fan's bearings, a loose connection in the wiring, or a failing motor that can no longer reach its target velocity.
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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Related fault codes
All 57 fault codes on the Highflow 250
Seeing a different code? Every code this model can display, in one place.