How much does it cost to fix Potterton error code Red LED is 'ON'?

Typical repair cost for the Potterton Red LED is 'ON' fault is £120-280 including labour.

Red LED is 'ON' High

Potterton Red LED is 'ON' Fault Code

Q: What does the Potterton Red LED is 'ON' fault code mean?

Your boiler has detected an internal electrical or safety fault and has stopped running to prevent damage.

Also written as REDLEDISON — same fault.

The Potterton Red LED is 'ON' fault code means: your boiler has detected an internal electrical or safety fault and has stopped running to prevent damage.. It appears on 2 Potterton models in our database.

Technical description: Boiler fails to work. Check: Electrical Plugs (PL1 to PL6) are connected to Circuit Board, Main Supply Voltage is between 196Vac & 253Vac, link plug is fitted (RSL models), or T.T.B. thermostat continuity (CFL models).

What causes the Potterton Red LED is 'ON' fault?

This fault occurs when the boiler's internal computer stops receiving signals from essential safety components or loses its electrical connection. It is usually caused by a loose wiring plug inside the unit or a component failing to complete an electrical circuit, which forces the boiler to shut down for safety. In some cases, fluctuations in your home's mains power supply can also trigger this red light.

Typical repair cost £120-280 (including labour)

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 Red LED is 'ON' fault code

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

Source

Potterton Red LED is 'ON' 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