E08 High

Ariston E08 Fault Code

The Ariston E08 fault code means: your boiler has switched off because a safety sensor in your underfloor heating system has detected the water is getting too hot and has triggered an automatic shutdown to prevent damage.. It appears on 9 Ariston models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Under floor heating system safety thermostat contact open (boiler shutdown both in D.H.W. mode and C.H. mode; boiler operation resumes automatically when the thermostat contact closes on cooling).
Typical repair cost £120-250 (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 E08 fault code

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

Source

Ariston E08 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 31 August 2026