High
41. on Saunier Duval Ecosy 24E

Your boiler's internal computer is experiencing a critical error and needs to be attended to by a professional to get your heating and hot water back up and running.

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

There is an internal fault in the Automatic Control Module.

From this model's manual
Verified against the Saunier Duval Ecosy 24e installation & service manual.
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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