High
ALL 12 on Sime Murelle Revolution 30

Your boiler's internal settings do not match the way it has been installed, meaning it cannot determine how to safely vent its exhaust fumes.

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

Incorrect configuration of the open / sealed chamber

From this model's manual
Verified against the Sime Murelle Revolution 30 installation & service manual, page 63.
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 13View →ALL 14View →

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