Fault B1 - No boiler temperature display or menu access

What does B1 mean?

The boiler displays a B1 fault code, which results in the boiler temperature not being displayed and inability to access system menus or installer setup. This indicates an issue with the programming unit or its connection.

• Low battery charge in the programming unit
• Incorrect dip switch settings on the programming unit
• Poor contact of the VR20 circuit board
• Defective VR20 board or programming unit

Click steps to track your progress.

1. 1

   Replace the batteries in the programming unit.

2. 2

   Check and adjust the dip switch settings on the rear of the programming unit.

3. 3

   Clear the fault code.

4. 4

   If the fault reappears, turn the boiler off, remove the VR20 circuit board, then power the boiler on.

5. 5

   Reinstall the VR20 circuit board, ensuring it makes positive contacts.

6. 6

   If the boiler starts but there is no temperature display, replace the VR20 board and programming unit.