BoilerFaultCodesWorcester Bosch 358 Fault Code
The Worcester Bosch 358 fault code means: your boiler is performing a routine self-cleaning cycle to prevent internal parts from getting stuck during periods of inactivity.. It appears on 12 Worcester Bosch models in our database.
Technical description: Anti-seizing functn. active
What causes the Worcester Bosch 358 fault?
This occurs when the boiler has been sitting idle for a long period without a request for heating or hot water. To prevent the internal pump and diverter valve from seizing up due to inactivity, the system automatically triggers a brief movement cycle to keep all mechanical components lubricated and moving freely.
This display is most common during the summer months when the central heating is turned off and the boiler is used less frequently.
DIY fix possible
Wait for 30 to 60 seconds for the operation to completeEnsure the boiler power remains switched onMonitor the display to confirm the code clears automatically
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Gas Safe Register →Worcester Bosch models that show the 358 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 358 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