BoilerFaultCodesWorcester Bosch A1 281 Fault Code
Also written as A1281 — same fault.
The Worcester Bosch A1 281 fault code means: your boiler has detected that water is not circulating properly, likely because the system pressure is too low or there is trapped air preventing the pump from working correctly.. It appears on 13 Worcester Bosch models in our database.
Technical description: Pump stuck or running in air Little or no water in the system.
DIY fix possible
Check the pressure gauge on the front of the boiler; if it is below 1 bar, you need to top it up using the filling loop.Once the pressure is between 1 and 1.5 bar, switch the boiler off at the fused spur for 30 seconds and then turn it back on to reset.If the error persists after repressurizing, ensure all radiator valves are fully open to allow water to circulate.
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 A1 281 fault code
Click a model for the full fault code list and model-specific repair notes.
- 24 RSF Repair: £180-350
- 26 CDi Xtra Repair: £120-£320
- 30i Junior Repair: £180-350
- 35 RSF Repair: £180-350
- Danesmoor Repair: £180-350
- Greenstar 12i System Repair: £150-350
- Greenstar 12i System Repair: £200-450
- Greenstar CDi Compact Repair: £120-250
- Greenstar i Repair: £150-300
- Heatslave Repair: £120-350
- Hideaway Repair: £150-£350
- Junior 24i Repair: £180-350
- Junior 28i Repair: £180-£350
Source
Worcester Bosch A1 281 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