How much does it cost to fix Chaffoteaux error code 8.i?

Typical repair cost for the Chaffoteaux 8.i fault is £80-150 including labour.

8.i Medium

Chaffoteaux 8.i Fault Code

Q: What does the Chaffoteaux 8.i fault code mean?

Your boiler is struggling because there is trapped air inside the heating system, which is making the pump sound noisy and preventing water from circulating properly.

Also written as 8I — same fault.

The Chaffoteaux 8.i fault code means: your boiler is struggling because there is trapped air inside the heating system, which is making the pump sound noisy and preventing water from circulating properly.. It appears on 3 Chaffoteaux models in our database.

Technical description: Pump noisy - Air in system

Typical repair cost £80-150 (including labour)

DIY fix possible

Turn off your boiler and let the radiators cool down completely.Use a radiator key to bleed every radiator in your home, starting from the lowest level and working your way up to the highest, until only water comes out.Check your boiler's pressure gauge and top it up to the manufacturer's recommended level (usually between 1 and 1.5 bar) using the filling loop.

Find a Gas Safe engineer

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

Gas Safe Register →

Chaffoteaux models that show the 8.i fault code

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

Source

Chaffoteaux 8.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