286 D1 Medium

Worcester Bosch 286 D1 Fault Code

Also written as 286D1 — same fault.

The Worcester Bosch 286 D1 fault code means: your boiler has detected that the water returning from your radiators and pipes is hotter than it should be, suggesting the system is struggling to regulate its temperature.. It appears on 3 Worcester Bosch models in our database.

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description: Return temperature too high
Typical repair cost £120-250 (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 286 D1 fault code

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

Source

Worcester Bosch 286 D1 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