BoilerFaultCodesWorcester Bosch C6215 Fault Code
The Worcester Bosch C6215 fault code means: your boiler has detected that the internal fan is spinning faster than it should, which has caused the system to shut down for safety.. It appears on 3 Worcester Bosch models in our database.
Technical description: Fan speed too high – check the fan harness and connector
What causes the Worcester Bosch C6215 fault?
This fault occurs when the boiler's control board loses its ability to regulate the fan's rotation, causing it to spin at an unsafe speed. The most common reason is a communication failure between the electronic heart of the boiler and the fan motor, often due to a faulty circuit board or a loose connection. In some cases, the fan motor itself has suffered internal damage and can no longer respond to the commands meant to slow it down.
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 C6215 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch C6215 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