How much does it cost to fix Ariston error code E03?

Typical repair cost for the Ariston E03 fault is £120-£280 including labour.

E03 High

Ariston E03 Fault Code

Q: What does the Ariston E03 fault code mean?

Your boiler has detected that it is getting dangerously hot even while it isn't supposed to be running, causing it to shut down for safety.

The Ariston E03 fault code means: your boiler has detected that it is getting dangerously hot even while it isn't supposed to be running, causing it to shut down for safety.. It appears on 3 Ariston models in our database.

Technical description: Flow temperature over 100°C while boiler is not in operation (stand-by)

Typical repair cost £120-£280 (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 E03 fault code

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

Genus 24 MFFI Repair: £120-250
Genus 27 Repair: £120-£280
Genus Premium Repair: £120-£280

Source

Ariston E03 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