How much does it cost to fix Chaffoteaux error code 5.ii?

Typical repair cost for the Chaffoteaux 5.ii fault is £90-180 including labour.

5.ii Medium

Chaffoteaux 5.ii Fault Code

Q: What does the Chaffoteaux 5.ii fault code mean?

Your boiler is struggling to provide hot water because the incoming mains water supply pressure is too low for the system to detect or operate correctly.

Also written as 5II — same fault.

The Chaffoteaux 5.ii fault code means: your boiler is struggling to provide hot water because the incoming mains water supply pressure is too low for the system to detect or operate correctly.. It appears on 3 Chaffoteaux models in our database.

Technical description: Hot water does not operate over temperature range - Low inlet water pressure

Typical repair cost £90-180 (including labour)

DIY fix possible

Check that the mains water stopcock under your kitchen sink is fully openEnsure no other taps in the house are fully open or leaking significantlyCheck if there are any current water supply maintenance works reported by your local water provider

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Chaffoteaux models that show the 5.ii fault code

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

Source

Chaffoteaux 5.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