High Lockout
E2233 on Worcester Bosch CDi Classic

Your boiler has lost communication with the internal thermometer that monitors water temperature, causing the system to shut down for safety.

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

Flow temperature sensor disconnected

What causes this fault?

This fault occurs when the boiler's main computer can no longer detect a signal from the sensor that monitors how hot the water is getting. It is usually caused by the sensor failing internally due to age, or a loose connection in the internal wiring that has broken the electrical circuit. Because the boiler cannot safely monitor its own temperature, it shuts down to prevent the system from 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

E9 224View →A7View →

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