6d Emergency

Worcester Bosch 6d Fault Code

Also written as 6D — same fault.

The Worcester Bosch 6d fault code means: your boiler has detected that a flame is still present inside the unit even though it should have turned off, which suggests a safety control issue.. It appears on 4 Worcester Bosch models 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: Flame detected after gas valve switched off
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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Worcester Bosch models that show the 6d fault code

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

Source

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

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026