BoilerFaultCodesWorcester Bosch C7 Fault Code
The Worcester Bosch C7 fault code means: your boiler has switched itself off because it cannot pull enough air through to safely burn the gas, so it will not provide any heat or hot water.. It appears on 11 Worcester Bosch models in our database.
Technical description: Fan problem - Fan not running or No airflow after a defined period of time
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Worcester Bosch models that show the C7 fault code
Click a model for the full fault code list and model-specific repair notes.
- 533 Compact
- 535 Compact
- Greenstar 25 Si Compact Repair: £250-450
- Greenstar 25Si Compact ErP Repair: £250-450
- Greenstar 27i System Compact ErP Repair: £250-450
- Greenstar 28CDi Compact ErP Repair: £250-450
- Greenstar 30 Si Compact Repair: £250-450
- Greenstar 30i System Compact ErP Repair: £250-450
- Greenstar 30Si Compact ErP Repair: £250-450
- Greenstar CDi Compact Repair: £250-450
- Greenstar Utility 18/25 Repair: £150-300
Source
Worcester Bosch C7 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.
- Worcester Bosch 535 Compact manual (PDF)
- Worcester Bosch Greenstar 30 Si Compact manual (PDF)
- Worcester Bosch Greenstar 30Si Compact ErP manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026