How much does it cost to fix Potterton error code THERMISTOR OPEN CIRCUIT?

Typical repair cost for the Potterton THERMISTOR OPEN CIRCUIT fault is £120-220 including labour.

THERMISTOR OPEN CIRCUIT High

Potterton THERMISTOR OPEN CIRCUIT Fault Code

Q: What does the Potterton THERMISTOR OPEN CIRCUIT fault code mean?

Your boiler has lost its connection to one of its temperature sensors and has shut down to prevent the system from overheating.

Also written as THERMISTOROPENCIRCUIT — same fault.

The Potterton THERMISTOR OPEN CIRCUIT fault code means: your boiler has lost its connection to one of its temperature sensors and has shut down to prevent the system from overheating.. It appears on 1 Potterton model in our database.

Technical description: Lockout LED flashing once every 4 seconds

Typical repair cost £120-220 (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 THERMISTOR OPEN CIRCUIT fault code

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

Performa System HE Repair: £120-220

Source

Potterton THERMISTOR OPEN CIRCUIT 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