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Halstead 1 Fault Code

The Halstead 1 fault code means: your boiler has detected that the water is getting too hot or is not circulating properly, causing it to shut down for safety.. It appears on 1 Halstead model in our database.

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: Abnormal temperatures (monitored by flow and return thermisters) will cause the appliance to go to lockout.
Typical repair cost £120-280 (including labour)

DIY fix possible

Check that all radiator valves are fully open.Ensure the central heating system pressure is between 1.0 and 1.5 bar.Try resetting the boiler to see if the fault clears.

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Halstead models that show the 1 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Halstead 1 fault code information on this page is sourced and cross-checked against the official Halstead service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026