712 Medium

Ariston 712 Fault Code

The Ariston 712 fault code means: your boiler is struggling to monitor the temperature of the water returning from the second heating zone, which may prevent some of your radiators from warming up correctly.. It appears on 1 Ariston model in our database.

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: Return sensor defective (zone 2)
Typical repair cost £110-190 (including labour)

Engineer required

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

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Ariston models that show the 712 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Ariston 712 fault code information on this page is sourced and cross-checked against the official Ariston service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026