High Lockout
09E on Ravenheat HE 80/90 / 25-30s

Your boiler has shut down because it has detected that the water inside is getting too hot, usually due to a circulation blockage or a pump failure.

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

Overheat sensor overheating

What causes this fault?

This fault occurs when the water inside the boiler exceeds a safe temperature limit, causing the safety sensors to shut the system down to prevent damage. The most common reasons are a pump that has seized and stopped moving water, or a buildup of debris and sludge that has physically blocked the heat exchanger.

This issue often surfaces in autumn when the heating is turned back on for the first time, as pumps can seize up after being idle during the summer months.

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

08EView →

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