BoilerFaultCodesWorcester Bosch C7217 Fault Code
The Worcester Bosch C7217 fault code means: your boiler's fan is failing to spin at the correct speed to begin the ignition process, preventing the boiler from firing up.. It appears on 2 Worcester Bosch models in our database.
Technical description: The fan speed is irregular when starting up
What causes the Worcester Bosch C7217 fault?
This fault occurs when the boiler's internal computer detects that the fan is not rotating fast enough to safely clear out the combustion chamber before ignition. The most common reason is a mechanical failure within the fan motor or a buildup of debris, though electronic issues with the control board can also stop the fan from receiving the correct power signals.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Worcester Bosch models that show the C7217 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch C7217 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026