BoilerFaultCodesWorcester Bosch E9220 Fault Code
The Worcester Bosch E9220 fault code means: your boiler has detected an unsafe level of heat or an electrical fault in its safety sensor and has locked down to prevent damage.. It appears on 1 Worcester Bosch model in our database.
Technical description: The contacts for the safety temperature sensor have shorted or the safety temperature sensor has detected a temperature higher than 130°c
What causes the Worcester Bosch E9220 fault?
This fault occurs when the boiler's internal safety components detect that the heat exchanger has reached a dangerously high temperature or there is a failure in the electrical sensor that monitors it. The most common reasons are a lack of water flow caused by a pump failure, a heavy build-up of debris in the system, or a faulty sensor sending an incorrect signal 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 E9220 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch E9220 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