Medium
S 25 on Ariston Genus Premium

Your boiler is struggling to read the temperature of the external hot water storage cylinder, which may result in a lack of hot water.

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

Tank sensor open

Engineer required

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

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S 26View →

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