10.iv High

Chaffoteaux 10.iv Fault Code

Also written as 10IV — same fault.

The Chaffoteaux 10.iv fault code means: your boiler is struggling to move heat away from its internal workings, causing it to quickly turn on and off as it tries to protect itself from overheating.. It appears on 3 Chaffoteaux models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Rapid cycling high/low or high/low/off - Blocked heat exchanger
Typical repair cost £150-300 (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 10.iv fault code

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

Source

Chaffoteaux 10.iv 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 7 July 2026