Anti-frost device Low

Ariston Anti-frost device Fault Code

Also written as ANTIFROSTDEVICE — same fault.

The Ariston Anti-frost device fault code means: your boiler has detected that the water inside is getting too cold and has automatically turned on its internal heater to prevent the pipes from freezing.. It appears on 1 Ariston model in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Pump activates if water temperature falls below 8°C until 18°C is attained; further protection triggers if temperature falls below 3°C.

DIY fix possible

Ensure the boiler remains plugged in and the power supply is switched onCheck that your gas supply is active so the burner can fire if neededOpen any radiator valves in colder rooms to allow water to circulate freely

Find a Gas Safe engineer

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

Gas Safe Register →

Ariston models that show the Anti-frost device fault code

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

Source

Ariston Anti-frost device 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