High
Overheat cut-off on Worcester Bosch 24si II

Your boiler has detected that it is getting too hot and has automatically shut itself down to prevent damage.

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.

What the manual says

Manufacturer manual

The fault indicator will flash once a second. An overheat cut-off thermostat is fitted to the appliance which will interrupt the electricity supply to the gas valve.

From this model's manual
Verified against the Worcester Bosch 24si Ii installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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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