High
AL 11 on Sime Murelle One HE

Your boiler has lost its electronic connection to the part that controls the gas flow, meaning it cannot safely stay lit to provide heating or hot water.

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

Gas valve modulator disconnected — check electrical connection to gas valve modulator

From this model's manual
Verified against the Sime Murelle One He 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 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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AL 01View →AL 06View →AL 12View →

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