High
1022 B on Worcester Bosch Greenstar 30i

Your boiler is struggling to accurately measure the temperature of your hot water, which usually means the internal sensor is either loose or has failed.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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.

What the manual says

Manufacturer manual

Hot water storage temperature sensor is defective – connect the plug to the hot water temperature sensor correctly, mount the hot water temperature sensor correctly or replace the hot water temperature sensor

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.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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