Likely causes
- Faulty flow sensor
- Wiring or plug fault
- PCB fault
What you can safely check
- Reset the boiler once; if the code comes straight back, call us
What our engineer does
We test the sensor and its wiring and replace the failed part. Anything involving the gas supply, gas valve, combustion chamber, flue, fan, PCB or heat exchanger must be left to a Gas Safe registered engineer and must not be attempted by the householder.
Models this applies to: Greenstar i, Greenstar Si, Greenstar CDi, Greenstar CDi Classic, Greenstar CDi Compact.
Boiler repairs from £90
Diagnosis and a fixed price before the repair. Most faults fixed on the first visit. Gas Safe 925538.
Other Worcester Bosch codes
Guidance only. Fault codes vary by model and firmware; anything involving gas, the flue, the fan, the gas valve, the PCB or the heat exchanger must be done by a Gas Safe registered engineer.
