High
ALL 04 on Sime Murelle Elite HE Combi

Your boiler is failing to detect the temperature of the water coming out of your hot taps, which means it cannot heat your hot water correctly.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

D.H.W. SENSOR ALARM

From this model's manual
Verified against the Sime Murelle Elite He Combi installation & service manual, page 31.
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 is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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ALL 01View →ALL 05View →

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