BoilerFaultCodesPotterton Safety Thermostat Neon Fault Code
Also written as SAFETYTHERMOSTATNEON — same fault.
The Potterton Safety Thermostat Neon fault code means: your boiler has switched itself off because it has detected that it is getting too hot inside.. It appears on 1 Potterton model in our database.
Technical description: Shut down the boiler in the event of the system, the boiler or the flue overheating.
What causes the Potterton Safety Thermostat Neon fault?
This fault occurs when the water inside the boiler reaches an unsafe temperature, triggering a safety switch to prevent damage. The most common reasons are a pump failure that stops water from moving or a blockage in the pipework that restricts flow. In some cases, the safety sensor itself may have become faulty and is reporting a high temperature incorrectly.
This issue often appears when the heating is first turned on after summer, as the internal pump can seize up during long periods of inactivity.
DIY fix possible
Check that all radiator valves are open and not blockedTurn the selector switch to the 'Reset' position and hold for at least five secondsEnsure the system pressure is between 1 and 1.5 bar on the pressure gauge
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Gas Safe Register →Potterton models that show the Safety Thermostat Neon fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton Safety Thermostat Neon 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 27 April 2026