D4 271 High

Worcester Bosch D4 271 Fault Code

Also written as D4271 — same fault.

The Worcester Bosch D4 271 fault code means: your boiler has detected that the water inside the unit is getting too hot compared to the water travelling to your radiators, causing it to shut down to prevent damage.. It appears on 11 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: Temperature difference between flow and safety sensors exceeds limit
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 D4 271 fault code

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

Source

Worcester Bosch D4 271 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