Medium
375 on Worcester Bosch Greenstar CDi Compact

Your boiler is having trouble reading the temperature of the incoming cold water, which may prevent it from providing consistent hot water.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

E4 Preheat sensor on DHW inlet Short Circuit

From this model's manual
Verified against the Worcester Bosch Greenstar Cdi Compact installation & service manual, page 66.
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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