Medium
F.03 on Vaillant ecoTEC plus Aquaplus

Your boiler has lost the connection to the temperature sensor inside your hot water tank, meaning it cannot determine how hot your water is.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

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

Tank-NTC: NTC broken; NTC cable broken; Defective connection at NTC; Defective connection at electronics | Tank- NTC cable defective/ broken NTC faulty

Engineer required

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

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Related fault codes

F.02View →

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