6C High

Buderus 6C Fault Code

The Buderus 6C fault code means: your boiler thinks there is a flame when there shouldn't be, or the sensor that detects the flame is sending a false signal, causing the system to shut down for safety.. It appears on 1 Buderus model 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: Blinking fault code: Ionisation message, but no flame
Typical repair cost £120-£280 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Buderus models that show the 6C fault code

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

Source

Buderus 6C fault code information on this page is sourced and cross-checked against the official Buderus service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026