High Lockout
E15 on Remeha Avanta 18V

Your boiler has stopped working because a sensor that monitors the temperature of the water returning to the unit has developed a fault.

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

NTC return sensor error

What causes this fault?

This fault occurs when the boiler's internal computer receives an illogical or missing signal from the sensor that measures water temperature coming back from your radiators. This is usually caused by the sensor physically failing due to age or a loose connection in the internal wiring preventing the control board from monitoring the system safely.

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

E1View →E6View →E14View →

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