How much does it cost to fix Ariston error code UU/FF?

Typical repair cost for the Ariston UU/FF fault is £120-350 including labour.

UU/FF High

Ariston UU/FF Fault Code

Q: What does the Ariston UU/FF fault code mean?

Your boiler is struggling to detect the flame it needs to stay lit safely, which is preventing the system from heating your home or water.

Also written as UUFF — same fault.

The Ariston UU/FF fault code means: your boiler is struggling to detect the flame it needs to stay lit safely, which is preventing the system from heating your home or water.. It appears on 3 Ariston models in our database.

Technical description: Ionisation current (expressed in bT)

Typical repair cost £120-350 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Ariston models that show the UU/FF fault code

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

Source

Ariston UU/FF 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