BoilerFaultCodesWorcester Bosch A1281 Fault Code
The Worcester Bosch A1281 fault code means: your boiler's internal pump is either jammed or struggling to move water because there is too much trapped air in the system.. It appears on 2 Worcester Bosch models in our database.
Technical description: Pump stuck or running with air in the system
What causes the Worcester Bosch A1281 fault?
This fault occurs when the boiler's internal pump is unable to circulate water because it is physically jammed or there is a large pocket of air preventing it from gaining traction. Over time, debris in the system water can seize the pump's moving parts, or air can enter the system after a period of inactivity or a recent repair.
This fault is more common in autumn when homeowners turn their heating back on for the first time, as pumps often seize after being idle throughout the summer.
DIY fix possible
Check your boiler pressure gauge and top it up to 1.5 bar if it is too lowBleed all of your radiators to remove trapped airGently restart the boiler using the reset button
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Gas Safe Register →Worcester Bosch models that show the A1281 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch A1281 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