High
40 on Viessmann Vitodens 100-W

Your boiler has stopped heating your water because it is receiving an incorrect signal from the temperature sensor inside your water cylinder.

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

Burner blocked: Cylinder temperature sensor shorted

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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