6 flashes High

Worcester Bosch 6 flashes Fault Code

Also written as 6FLASHES — same fault.

The Worcester Bosch 6 flashes fault code means: your boiler's temperature sensor is failing to communicate correctly, which prevents the system from knowing how hot the water is and causes it to shut down for safety.. It appears on 3 Worcester Bosch models 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: CH flow NTC sensor defective. Check CH flow NTC sensor and connecting lead.
Typical repair cost £90-160 (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 6 flashes fault code

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

Source

Worcester Bosch 6 flashes 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