High Lockout
E45 on Vokera Condexa Pro

Your boiler has lost connection with the sensor that monitors water returning from your radiators, meaning it cannot safely regulate its temperature.

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

Return probe with contact open

What causes this fault?

This fault occurs when the boiler's control board stops receiving a signal from the sensor that monitors the temperature of the water coming back from your heating system. The most common cause is a failed internal sensor or a loose wire connection, which prevents the boiler from knowing if the system is overheating.

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

E 44View →E 40View →E 41View →

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