High Lockout
E9285 on Worcester Bosch GB162

Your boiler has shut down because it thinks the water returning to the unit is dangerously hot, which usually means water isn't circulating properly through your radiators.

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

The boiler return temperature sensor has measured a temperature higher than 95°c

What causes this fault?

This fault occurs when the water coming back into the boiler is too hot, causing the system to shut down for safety. The most common reason is a lack of water flow, often caused by a failing pump or a blockage in the pipework that prevents heat from escaping to your radiators. If the water cannot move, it stays inside the boiler and quickly overheats.

This fault is more frequent when you first turn your heating back on in autumn, as pumps can seize up after being idle over 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

E9 219View →E9 224View →

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