What does the Worcester Bosch EF fault code mean?

Your boiler has detected that the water inside isn't warming up as expected after it fires up, so it has stopped trying to prevent potential damage.

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

Typical repair cost for the Worcester Bosch EF fault is £150-350 including labour.

Supply and/or return temperatures do not change after burner start

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.

Each noise points to a different fault.

7 signs repair isn't worth it anymore.