How much does it cost to fix Chaffoteaux error code 6.i?

Typical repair cost for the Chaffoteaux 6.i fault is £120-250 including labour.

6.i High

Chaffoteaux 6.i Fault Code

Q: What does the Chaffoteaux 6.i fault code mean?

Your boiler has stopped heating because it is not detecting enough water flowing through the system, which is a safety mechanism to prevent it from overheating.

Also written as 6I — same fault.

The Chaffoteaux 6.i fault code means: your boiler has stopped heating because it is not detecting enough water flowing through the system, which is a safety mechanism to prevent it from overheating.. It appears on 3 Chaffoteaux models in our database.

Technical description: No main burner - Lack of water flow

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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Chaffoteaux models that show the 6.i fault code

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

Source

Chaffoteaux 6.i fault code information on this page is sourced and cross-checked against the official Chaffoteaux service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026