High Lockout
E2223 on Worcester Bosch GB162

Your boiler has lost connection with a internal sensor that monitors water temperature, meaning it cannot safely heat your home until the connection is restored.

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

The flow temperature sensor contacts have been interrupted

What causes this fault?

This fault occurs when the boiler's main control board loses electrical contact with the sensor that monitors the temperature of the water leaving the unit. The most common reason is a physical failure of the internal sensor's sensitive components or a loose connection in the wiring harness caused by natural heat expansion and vibration over time.

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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