The Vaillant VR 32/3 is a bus coupler for use with ecoTEC and ecoCRAFT 3 boilers. It is needed for cascade installations and allows the VRC 630/2 controller to identify the boilers connected to it. The Vaillant VR 32/3 sits alongside the boiler main PCB and connects via an interface cable. A simple numbered rotary switch is used to set the address of the boiler. The Vaillant VR 32/3 can then be connected to the VRC 630/2 controller using the eBUS terminals.