723 Medium

Ariston 723 Fault Code

The Ariston 723 fault code means: your boiler has detected that the third heating zone is getting too hot, likely due to a circulation problem or a faulty sensor in that specific area of your home.. 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: Overheating in zone 3
Typical repair cost £120-250 (including labour)

DIY fix possible

Check that all radiator valves in Zone 3 are open and not turned off.Ensure there are no obstructions around any localized zone pumps or valves.Try resetting the boiler to see if the error was a temporary sensor glitch.

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →

Ariston models that show the 723 fault code

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

Source

Ariston 723 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