dd.. Low

Ariston dd.. Fault Code

Also written as DD — same fault.

The Ariston dd.. fault code means: this is a normal operational message indicating that the boiler is currently heating water for your taps or shower.. 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: Domestic hot water, burner on

DIY fix possible

No action is required as this is a status indicator rather than a faultTurn off the hot water tap to see the code disappearCheck that no taps are dripping if the code stays on when water is not in use

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Ariston models that show the dd.. fault code

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

Source

Ariston dd.. 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