High
EF 349 on Worcester Bosch Greenstar 12i System

Your boiler has detected that it cannot move water through your radiators or pipes fast enough, causing the internal temperature to rise dangerously high.

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

Central heating, boil detect. Large delta T despite minimum burner.

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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Related fault codes

EAView →E9View →

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