What does the Worcester Bosch 1021 B fault code mean?

Your boiler's hot water sensor isn't communicating with the system, which means it cannot safely or accurately heat your water.

How much does it cost to fix Worcester Bosch error code 1021 B?

Typical repair cost for the Worcester Bosch 1021 B fault is £90-160 including labour.

Hot water temperature sensor is defective – the plug to the hot water temperature sensor may not be connected

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

Almost always a stuck diverter valve on combis.

Safety-critical — turn off, read this.

7 signs repair isn't worth it anymore.