How much does it cost to fix Ariston error code 1 1 8?

Typical repair cost for the Ariston 1 1 8 fault is £120-220 including labour.

1 1 8 High

Ariston 1 1 8 Fault Code

Q: What does the Ariston 1 1 8 fault code mean?

Your boiler is struggling to detect the temperature of the water inside because one of its internal sensors is sending an incorrect or missing signal.

Also written as 118 — same fault.

The Ariston 1 1 8 fault code means: your boiler is struggling to detect the temperature of the water inside because one of its internal sensors is sending an incorrect or missing signal.. It appears on 1 Ariston model in our database.

Technical description: Primary circuit probe problem

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 1 1 8 fault code

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

HS Premium Repair: £120-220

Source

Ariston 1 1 8 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