Retrofitting your Model B1 Controller to the Model B2 will give you the full functionality of the Model B2. You will have the three operational modes selectable using either the remote control transmitter or a manual three-way switch that you would source. The Model B1 has the three modes of operation, but you could only select the Always Closed option using a manual switch. The remote only enabled the Normal and Always Open.
Now, with the retrofit kit, you can convert your Model B1 to a Model B2 and have all three operational modes available to select using either the remote or a manual switch.
The Retrofit Kit comes complete with everything you need to convert your existing controller:
The additional function that you will gain over the Model B1 is the ability to select the Always Closed option using the remote. Otherwise, the Model B1 and Model B2 have identical operating characteristics.
Retrofitting your Model B1 is straight forward. You only need to disconnect the wires from the existing Printed Circuit Board (PCB), remove it from the enclosure, insert the new PCB and reconnect the wires. The only tools you will need are small wire cutters, an 8mm nut driver or socket, a small needle-nose plier or tweezer, a common small flat blade screwdriver and a small Philips screwdriver.