Frequent sooting (4) Emergency

Chaffoteaux Frequent sooting (4) Fault Code

Also written as FREQUENTSOOTING4 — same fault.

The Chaffoteaux Frequent sooting (4) fault code means: your boiler is struggling to breathe because the exhaust system is blocked, which creates a significant risk of dangerous gases building up in your home.. It appears on 1 Chaffoteaux model in our database.

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

Technical description: Restriction in flue.
Typical repair cost £150-350 (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 Frequent sooting (4) fault code

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

Source

Chaffoteaux Frequent sooting (4) 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