BoilerFaultCodesWorcester Bosch FD 231 Fault Code
Also written as FD231 — same fault.
The Worcester Bosch FD 231 fault code means: your boiler has detected an unexpected interruption or irregularity in its electrical power supply, which has caused it to stop working for safety.. It appears on 12 Worcester Bosch models in our database.
Technical description: Mains power fault – electrical power interruption
DIY fix possible
Check if there has been a recent power cut or if a fuse has tripped in your home's consumer unit.Restart the boiler by pressing and holding the reset button for five seconds.Ensure the boiler's fused spur switch is fully turned on and hasn't been accidentally knocked.
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 FD 231 fault code
Click a model for the full fault code list and model-specific repair notes.
- 24 RSF Repair: £0-120
- 26 CDi Xtra Repair: £90-280
- 30i Junior Repair: £0-120
- 35 RSF Repair: £0-120
- Danesmoor Repair: £80-250
- Greenstar 12i System Repair: £80-150
- Greenstar CDi Compact Repair: £90-180
- Greenstar i Repair: £120-250
- Heatslave Repair: £0-120
- Hideaway Repair: £0-250
- Junior 24i Repair: £0-280
- Junior 28i Repair: £100-350
Source
Worcester Bosch FD 231 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