BoilerFaultCodesWhat the manual says
Manufacturer manualFan speed too low – the fan lead and connector need checking and may need replacing.
From this model's manual
Verified against the Worcester Bosch Cdi Classic installation & service manual, page 54.
What causes this fault?
This fault occurs when the boiler's control board detects that the fan is not spinning at the required speed to safely expel exhaust fumes. The most common reasons are a build-up of dust and debris within the fan motor bearings or an electrical failure in the wiring that connects the fan to the main power supply.
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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