Unknown
D on Worcester Bosch 24i / 28i Junior

Worcester Bosch 24i / 28i Junior fault code D

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

What the manual says

Manufacturer manual

Ignition lockout, Overheat lockout, Internal error. Causes: No gas or low gas pressure, Weak spark or spark not across electrodes, Gas valve leaking or failed, Low water pressure or boiler dry, Pump fail, Primary sensor position, Flame sensor fail or connector, Overheat stat tripped or disconnected or faulty, Blocked burner, Blocked heat exchanger, Faulty Harness, Board fault.

From this model's manual
Verified against the Worcester Bosch/Worcester Bosch Junior 28i installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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All 27 fault codes on the 24i / 28i Junior

Seeing a different code? Every code this model can display, in one place.

24i28i200203208265AA1A8BCEFF1F2Flash once per secondGHILight onNo CH function (DHW OK)No DHW function (CH OK)No lights and no functions (with demand)rET1T3

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