High
E09 on Remeha Avanta 18V

Your boiler is overheating because water isn't moving through the system fast enough to transfer heat away from the burner.

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

Temperature increase too fast (T1 - T2 > 45°C): No or insufficient water flow

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

E04View →E06View →E10View →

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