ANTI-FROST DEVICE ACTIVATED Low

Ariston ANTI-FROST DEVICE ACTIVATED Fault Code

Also written as ANTIFROSTDEVICEACTIVATED — same fault.

The Ariston ANTI-FROST DEVICE ACTIVATED fault code means: your boiler has detected that the water inside the system is getting dangerously cold and has automatically fired up to prevent the pipes from freezing.. It appears on 3 Ariston models 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: Protection is activated if heating temperature is < 5°C.

DIY fix possible

Ensure your heating is set to at least 15°C if you are away during cold weather.Check that your external condensate pipe is not frozen or blocked with ice.Wait for the boiler to complete its automatic heating cycle; it will turn off once the water is warm enough.

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 ACTIVATED fault code

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

Source

Ariston ANTI-FROST DEVICE ACTIVATED 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