BoilerFaultCodesWorcester Bosch E9277 Fault Code
The Worcester Bosch E9277 fault code means: your boiler has shut down because it has detected internal water temperatures that are dangerously high, likely due to a circulation or sensor issue.. It appears on 1 Worcester Bosch model in our database.
Technical description: The safety temperature sensor has measured temperature in excess of 95°c
What causes the Worcester Bosch E9277 fault?
This fault occurs when the water inside the boiler’s heat exchanger becomes too hot, triggering a safety shutdown to prevent damage. The most common reasons are a pump failure that stops water from moving through the system or a blockage caused by a buildup of debris and sludge. In some cases, the internal sensor itself may have failed and is providing an incorrect temperature reading to the control board.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Worcester Bosch models that show the E9277 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch E9277 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