BoilerFaultCodesWorcester Bosch F0 (239) Fault Code
Also written as F0239 — same fault.
The Worcester Bosch F0 (239) fault code means: your boiler's internal computer has suffered a critical failure and can no longer communicate with its own systems to safely run your heating or hot water.. It appears on 11 Worcester Bosch models in our database.
Technical description: Control box or the HCM is defective.
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 F0 (239) fault code
Click a model for the full fault code list and model-specific repair notes.
- 24 RSF Repair: £280-550
- 26 CDi Xtra Repair: £250-£450
- 30i Junior Repair: £280-500
- 35 RSF Repair: £250-£450
- Danesmoor Repair: £250-£450
- Greenstar 12i System Repair: £250-450
- Greenstar i Repair: £250-450
- Heatslave Repair: £250-£450
- Hideaway Repair: £280-£550
- Junior 24i Repair: £280-550
- Junior 28i Repair: £250-£450
Source
Worcester Bosch F0 (239) 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