Medium
7 12 on Ariston Clas Net One

Your boiler is having trouble reading the temperature of the water coming back from your secondary heating zone, which may prevent that part of your home from warming up properly.

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

Zone 2 return sensor defective

Engineer required

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

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