Medium
No CH function (DHW OK) on Worcester Bosch 24i / 28i Junior

Your boiler is still providing hot water normally, but it is not responding to your heating controls or timer to warm up your home.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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.

What the manual says

Manufacturer manual

No link at ST2 Ls to Lr, or failed external control input to Lr. Failed programmer. Board fault.

Shared across the 24i / 28i Junior range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s 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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Related fault codes

EAView →D1View →A1View →

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

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

24i28i200203208265AA1A8BCDEFF1F2Flash once per secondGHILight onNo DHW function (CH OK)No lights and no functions (with demand)rET1T3

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