How much does it cost to fix Ariston error code 6 12?

Typical repair cost for the Ariston 6 12 fault is £180-350 including labour.

6 12 High

Ariston 6 12 Fault Code

Q: What does the Ariston 6 12 fault code mean?

Your boiler has detected that the internal fan responsible for venting exhaust gases is not spinning or reporting its speed correctly, preventing the boiler from starting safely.

Also written as 612 — same fault.

The Ariston 6 12 fault code means: your boiler has detected that the internal fan responsible for venting exhaust gases is not spinning or reporting its speed correctly, preventing the boiler from starting safely.. It appears on 12 Ariston models in our database.

Technical description: Incorrect measurement of fan speed

Typical repair cost £180-350 (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 6 12 fault code

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

Source

Ariston 6 12 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