Medium
3 flashes on Worcester Bosch Greenstar 25CDi

Your boiler's hot water temperature sensor has stopped working, which means the system cannot accurately heat your 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

Hot water NTC sensor defective. Check hot water NTC sensor and connecting lead for circuit breaks/short circuits.

From this model's manual
This code was read directly from the manufacturer service manual for this model.
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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