Power ON LED (Green) blinking High

Halstead Power ON LED (Green) blinking Fault Code

Also written as POWERONLEDGREENBLINKING — same fault.

The Halstead Power ON LED (Green) blinking fault code means: your boiler has detected that there is either not enough water inside the heating system or the sensor responsible for detecting flow is not operating correctly.. 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: Indicates a fault with the water pressure or flow switch (primary flow switch contacts open).
Typical repair cost £120-220 (including labour)

DIY fix possible

Check your boiler's pressure gauge and ensure it is between 1 and 1.5 bar.If the pressure is low, locate the filling loop under the boiler to top up the system.Once the pressure is correct, restart the boiler to see if the blinking light stops.

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Halstead models that show the Power ON LED (Green) blinking fault code

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

Source

Halstead Power ON LED (Green) blinking 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