BoilerFaultCodesHalstead 5 Fault Code
The Halstead 5 fault code means: your boiler has shut down because a temperature sensor is faulty or the main unit has become too hot to operate safely.. It appears on 1 Halstead model in our database.
Technical description: Defective sensor or thermal fuse gone - Defective flow, return or flue sensor, or heat exchanger reached maximum safe working temperature
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Halstead models that show the 5 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Halstead 5 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