Low
H11 on Worcester Bosch Greenstar Heatslave II

Your boiler has identified a minor fault with a sensor that monitors the incoming mains cold water, but your heating and hot water will continue to work absolutely fine.

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

DCW in sensor defect, (appliance operation not affected)

From this model's manual
Verified against the Worcester Bosch Greenstar Heatslave Ii installation & service manual, page 43.
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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