How much does it cost to fix Ariston error code S 27?

Typical repair cost for the Ariston S 27 fault is £150-300 including labour.

S 27 High

Ariston S 27 Fault Code

Q: What does the Ariston S 27 fault code mean?

Your boiler has detected that the water inside its internal storage tank is reaching dangerously high temperatures and has shut itself down to prevent damage or safety risks.

Also written as S27 — same fault.

The Ariston S 27 fault code means: your boiler has detected that the water inside its internal storage tank is reaching dangerously high temperatures and has shut itself down to prevent damage or safety risks.. It appears on 5 Ariston models in our database.

Technical description: Tank overheating

Typical repair cost £150-300 (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 S 27 fault code

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

Source

Ariston S 27 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