High
E07 on Keston Celsius 30

Your boiler has sensed that the exhaust gases are getting too hot, which often indicates the main heat exchanger is blocked or struggling to transfer heat correctly.

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

Flue overheat – check combustion and flue temperature vs. return temperature – the flue temperature should be no more than 10C above return temperature. Possible heat exchanger fault.

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

E08View →E09View →

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