How much does it cost to fix Chaffoteaux error code 18?

Typical repair cost for the Chaffoteaux 18 fault is £100-280 including labour.

18 High

Chaffoteaux 18 Fault Code

Q: What does the Chaffoteaux 18 fault code mean?

Your boiler has failed to light several times and is trying again, which usually means it is struggling to detect a flame or there is a problem with the gas supply.

The Chaffoteaux 18 fault code means: your boiler has failed to light several times and is trying again, which usually means it is struggling to detect a flame or there is a problem with the gas supply.. It appears on 6 Chaffoteaux models in our database.

Technical description: Attempt to re ignite

Typical repair cost £100-280 (including labour)

DIY fix possible

Check that your gas emergency control valve is in the 'on' positionIf you have a prepay meter, check that you have sufficient creditCheck if other gas appliances, like a hob, are working correctlyPress the Reset button to see if the boiler clears the fault

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Chaffoteaux models that show the 18 fault code

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

Source

Chaffoteaux 18 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