5 02 Emergency

Chaffoteaux 5 02 Fault Code

Also written as 502 — same fault.

The Chaffoteaux 5 02 fault code means: your boiler has detected a flame inside the unit even though it should have shut the gas supply off, which is a significant safety concern.. 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: Détection de flamme avec la vanne gaz fermée
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 5 02 fault code

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

Source

Chaffoteaux 5 02 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