Medium
305 on Worcester Bosch Greenstar 30i

Your boiler is confused and thinks you are still running a hot tap elsewhere in the house, preventing it from switching back to heating mode.

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

The boiler is waiting for domestic hot water (DHW) operation to end

Shared across the 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.

DIY fix possible

Check that all hot water taps in the house are fully turned off.Ensure any thermostatic mixer showers are turned off and not leaking.Reset the boiler by turning the control knob to the 'Reset' position for five seconds.

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