Worcester Bosch · Greenstar Si Compact ErP
FD 231Mains power interruption error
This code applies to Greenstar 25Si Compact ErP, Greenstar 30Si Compact ErP. Fault codes narrow down the likely problem, but they do not replace a model-specific diagnosis.
What you can safely check
- Check for a wider power cut or a tripped consumer-unit circuit without removing the boiler case.
- Use a qualified electrician or Gas Safe engineer for further diagnosis.
How an engineer may fix it
Verify supply voltage, polarity, earthing, fuses, harnesses and appliance electronics; correct the electrical supply or replace the failed component.
Manufacturer source: Worcester Bosch — Greenstar Si Compact ErP Installation, Commissioning and Servicing Instructions (6 720 813 278). Checked 15 August 2026. The appliance manual and an engineer’s on-site diagnosis take precedence. Never remove the boiler case yourself.