Red LED (Illuminated) Emergency

Potterton Red LED (Illuminated) Fault Code

Also written as REDLEDILLUMINATED — same fault.

The Potterton Red LED (Illuminated) fault code means: your boiler has shut down because it has either become too hot or detected that dangerous exhaust fumes are not escaping correctly through the chimney.. It appears on 5 Potterton models in our database.

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

Technical description: Overheat condition has occurred or Products Discharge Safety Device (TTB) has operated due to flue blockage.

What causes the Potterton Red LED (Illuminated) fault?

This fault occurs when the boiler's internal temperature or flue gases exceed safe limits, triggering a safety shut-off to protect your home. The most common reasons are a failure in the pump preventing water from moving through the system or a blockage in the chimney preventing exhaust fumes from escaping.

This issue often arises during the first cold spell of autumn, when a pump that has been idle all summer fails to seize or move water correctly upon restart.

Typical repair cost £90-250 (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 (Illuminated) fault code

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

Source

Potterton Red LED (Illuminated) 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