High
41. on Saunier Duval Ecosy

Your boiler's electronic command center has encountered a serious internal error and has stopped working to prevent further damage.

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.

Technical description

There is an internal fault in the Automatic Control Module.

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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