High
F29 on Saunier Duval Semia Condens F30 E

Your boiler has detected that a critical internal safety component has tripped, which means it has safely shut itself down to prevent potential overheating.

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

Thermal fuse. Replace the heat exchanger

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

F28View →

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