Worcester Bosch 224 / E9 Fault Code
Also written as 224E9 — same fault.
The Worcester Bosch 224 / E9 fault code means: your boiler has detected that it has become too hot and has automatically switched itself off to prevent any damage to the unit.. It appears on 1 Worcester Bosch model in our database.
Technical description: MAX thermostat activated
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 224 / E9 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 224 / E9 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