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

Typical repair cost for the Chaffoteaux 6.ii fault is £150-250 including labour.

6.ii High

Chaffoteaux 6.ii Fault Code

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

Your boiler is failing to start because the internal pump, which is responsible for moving water through your heating system, is stuck or blocked.

Also written as 6II — same fault.

The Chaffoteaux 6.ii fault code means: your boiler is failing to start because the internal pump, which is responsible for moving water through your heating system, is stuck or blocked.. It appears on 3 Chaffoteaux models in our database.

Technical description: No main burner - Pump jammed

Typical repair cost £150-250 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →

Chaffoteaux models that show the 6.ii fault code

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

Source

Chaffoteaux 6.ii 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