1 green flash High

Potterton 1 green flash Fault Code

Also written as 1GREENFLASH — same fault.

The Potterton 1 green flash fault code means: your boiler has detected that it is getting too hot and has paused operation to prevent damage.. It appears on 1 Potterton 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: Temperature Protection warning
Typical repair cost £100-£350 (including labour)

DIY fix possible

Check that all radiator valves are open to allow water to flow.Ensure there is enough water pressure in the system by checking the gauge.Turn the boiler off and back on at the main power switch to reset the sequence.

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Potterton models that show the 1 green flash fault code

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

Source

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

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