Medium
A09 on Ariston Clas One

Your boiler is struggling to accurately detect the temperature of the water it is heating for your taps and shower.

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

Domestic Hot Water NTC

Engineer required

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

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Related fault codes

A08View →A10View →

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