Thermostat + Low

Potterton Thermostat + Fault Code

Also written as THERMOSTAT — same fault.

The Potterton Thermostat + fault code means: your boiler is correctly receiving a signal from your thermostat that it needs to turn on, so this light simply indicates that your heating or hot water is currently in active mode.. It appears on 2 Potterton models in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Indicator light on control panel signaling heat demand/thermostat status

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 Thermostat + fault code

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

Source

Potterton Thermostat + 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