How much does it cost to fix Ariston error code UU/5?

Typical repair cost for the Ariston UU/5 fault is £0-120 including labour.

UU/5 Low

Ariston UU/5 Fault Code

Q: What does the Ariston UU/5 fault code mean?

Your boiler is displaying the current temperature of the hot water leaving the unit, which is usually an informative status update rather than a critical system failure.

Also written as UU5 — same fault.

The Ariston UU/5 fault code means: your boiler is displaying the current temperature of the hot water leaving the unit, which is usually an informative status update rather than a critical system failure.. It appears on 3 Ariston models in our database.

Technical description: Domestic hot water output temperature (C°)

Typical repair cost £0-120 (including labour)

DIY fix possible

Check if any hot water taps are currently runningMonitor the display to see if the code changes to a temperature reading or standby modeReset the boiler if the code remains frozen on the screen for a long period

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Ariston models that show the UU/5 fault code

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

Source

Ariston UU/5 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