Medium
ALL 04 on Sime Murelle HE System

Your boiler has detected a communication problem with the part that monitors the temperature of your hot water, which may cause your hot water to stop working or not reach the correct temperature.

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

D.H.W. SENSOR ALARM

From this model's manual
Verified against the Sime Murelle He System installation & service manual, page 28.
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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ALL 01View →ALL 05View →

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