BoilerFaultCodesWorcester Bosch C4 273 Fault Code
Also written as C4273 — same fault.
The Worcester Bosch C4 273 fault code means: your boiler has detected a small airflow issue while running its daily safety self-test, often meaning it needs a professional service or a minor part cleaned.. It appears on 12 Worcester Bosch models in our database.
Technical description: Airflow present during last 24 hour
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Worcester Bosch models that show the C4 273 fault code
Click a model for the full fault code list and model-specific repair notes.
- 24 RSF Repair: £0-80
- 26 CDi Xtra Repair: £90-180
- 30i Junior Repair: £0-180
- 35 RSF Repair: £120-350
- Danesmoor Repair: £80-180
- Greenstar 12i System Repair: £150-300
- Greenstar CDi Compact Repair: £150-300
- Greenstar i Repair: £150-250
- Heatslave Repair: £120-£350
- Hideaway Repair: £120-280
- Junior 24i Repair: £90-250
- Junior 28i Repair: £150-350
Source
Worcester Bosch C4 273 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