High
1 on Halstead Club HE 18

Your boiler has detected that the water is getting too hot or is not circulating properly, causing it to shut down for safety.

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

Abnormal temperatures (monitored by flow and return thermisters) will cause the appliance to go to lockout.

From this model's manual
Verified against the Halstead Club He 18 installation & service manual, page 30.
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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