A19 Medium

Ariston A19 Fault Code

The Ariston A19 fault code means: your boiler has detected a communication error with its internal control system and needs a simple restart to try and clear the fault.. It appears on 4 Ariston models 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: Try resetting the boiler
Typical repair cost £100-250 (including labour)

DIY fix possible

Locate the Reset button on the boiler control panel.Press and hold the Reset button for 3 to 5 seconds.Wait a few minutes to see if the boiler restarts and the error code clears.

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Ariston models that show the A19 fault code

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

Source

Ariston A19 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 7 July 2026