Worcester Bosch E9285 Fault Code
The Worcester Bosch E9285 fault code means: your boiler has shut down because it thinks the water returning to the unit is dangerously hot, which usually means water isn't circulating properly through your radiators.. It appears on 1 Worcester Bosch model in our database.
Technical description: The boiler return temperature sensor has measured a temperature higher than 95°c
What causes the Worcester Bosch E9285 fault?
This fault occurs when the water coming back into the boiler is too hot, causing the system to shut down for safety. The most common reason is a lack of water flow, often caused by a failing pump or a blockage in the pipework that prevents heat from escaping to your radiators. If the water cannot move, it stays inside the boiler and quickly overheats.
This fault is more frequent when you first turn your heating back on in autumn, as pumps can seize up after being idle over the summer months.
DIY fix possible
Check that all radiator valves are fully openEnsure the boiler pressure gauge is between 1 and 1.5 barCheck that the external pump (if visible) is running and not stuck
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Gas Safe Register →Worcester Bosch models that show the E9285 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch E9285 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