Medium
F.13 on Vaillant ecoTEC Plus 826

Your boiler is struggling to accurately measure the temperature of the water inside your hot water cylinder because of a faulty connection or wiring issue.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

Cylindertemperature sensorshortcircuit

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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