E01-943 High

Worcester Bosch E01-943 Fault Code

Also written as E01943 — same fault.

The Worcester Bosch E01-943 fault code means: your boiler is having trouble venting exhaust gases correctly, likely because the external flue pipe configuration is not communicating properly with the sensors.. It appears on 1 Worcester Bosch 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: Extension Flue Kit
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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Worcester Bosch models that show the E01-943 fault code

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

Source

Worcester Bosch E01-943 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 7 July 2026