High Lockout
E05 on Potterton Gold Combi HE

Your boiler's temperature sensor responsible for your heating system has developed a fault, meaning the boiler cannot accurately measure how hot the water is.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Central heating flow NTC sensor fault

What causes this fault?

This fault occurs when the sensor responsible for monitoring the temperature of the water leaving your boiler fails to send a correct electrical signal. The most common reason is that the internal component of the sensor has degraded over time or developed a short circuit, preventing the boiler from safely knowing how hot it is. In some cases, the issue may also be caused by loose or corroded wiring connecting the sensor to the main control board.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

E02View →E06View →E20View →

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