BoilerFaultCodesWorcester Bosch 9A362 Fault Code
The Worcester Bosch 9A362 fault code means: your boiler’s internal computer chip is unrecognized or has been installed incorrectly, causing the system to stop working for safety reasons.. It appears on 1 Worcester Bosch model in our database.
Technical description: error – incorrect HCM fitted
What causes the Worcester Bosch 9A362 fault?
This fault occurs when the boiler's main control board cannot communicate with the small data chip that identifies the specific model and power output. The most common reason is that this chip has worked loose from its socket, or it has been replaced with a version that is incompatible with the rest of the components. Because the system doesn't know exactly which model it is, it shuts down as a safety precaution to prevent incorrect operation.
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 9A362 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 9A362 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