How much does it cost to fix Ariston error code E74?

Typical repair cost for the Ariston E74 fault is £120-220 including labour.

E74 High

Ariston E74 Fault Code

Q: What does the Ariston E74 fault code mean?

Your boiler is struggling to accurately measure the temperature of the water circulating back from your radiators, so it has shut down as a precaution to prevent overheating.

The Ariston E74 fault code means: your boiler is struggling to accurately measure the temperature of the water circulating back from your radiators, so it has shut down as a precaution to prevent overheating.. It appears on 3 Ariston models in our database.

Technical description: Heating return temperature probe in short circuit

Typical repair cost £120-220 (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 E74 fault code

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

Source

Ariston E74 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