Low
358 on Worcester Bosch Greenstar Heatslave II

Your boiler is automatically moving a internal valve to keep it from sticking, which is a normal maintenance feature rather than a fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

Three way valve anti-seize: Anti-seize operation. If the diverter valve has not moved in 24 hours, the valve is operated to prevent seizing, duration approximately 10seconds.

From this model's manual
Verified against the Worcester Bosch Greenstar Heatslave Ii installation & service manual, page 29.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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