BoilerFaultCodesPotterton Red LED (Overheat) Fault Code
Also written as REDLEDOVERHEAT — same fault.
The Potterton Red LED (Overheat) fault code means: your boiler has switched itself off because it has gotten too hot, likely due to a circulation problem or a temporary blockage.. It appears on 3 Potterton models in our database.
Technical description: It will require manual re-setting if an overheat condition occurs (the LED will go Red).
What causes the Potterton Red LED (Overheat) fault?
This fault occurs when the water inside the heat exchanger reaches a dangerously high temperature, triggering a safety shut-off. The most common reasons are a failing pump that isn't moving water away from the boiler quickly enough or a buildup of debris and sludge that is restricting the flow. Essentially, the boiler is generating heat but has no way to vent it into your radiators.
This fault is more frequent in autumn when heating systems are first turned on after a long summer break, as internal pumps often seize during months of inactivity.
DIY fix possible
Ensure all radiator valves are fully open and there is no air in the system.Allow the boiler to cool down completely for at least 20 minutes.Locate the manual reset button (usually behind the front flap or underneath) and press it firmly to clear the red light.
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Gas Safe Register →Potterton models that show the Red LED (Overheat) fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton Red LED (Overheat) 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