BoilerFaultCodesPotterton 1 flash green Fault Code
Also written as 1FLASHGREEN — same fault.
The Potterton 1 flash green fault code means: your boiler has shut down because the water inside it has become too hot, too quickly, or is not circulating properly.. It appears on 1 Potterton model in our database.
Technical description: Temperature protection (Maximum flow temperature exceeded, Flow temperature rise rate too high, Excessive difference between flow and return temperature)
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Potterton models that show the 1 flash green fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton 1 flash green 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