Which of the following is a controller type that uses two wires in its conventional setup?

• A. Hybrid Controller
• B. Conventional/Two-Wire Controller
• C. Central Controller
• D. Internet Based Controller

Answer: (B)

In this area, the key idea is how the field wiring is arranged. A conventional two-wire controller uses just a single pair of conductors to carry both power and control signals to all zone valves. Each valve location has a small interface module that responds to the controller’s command, allowing only the selected zone to energize while the others stay off. This simple two-wire setup is what defines the conventional two-wire approach: minimal wiring, easy to install, and historically common.

Other controller types involve different architectures or connectivity, such as central controllers coordinating from a remote location or internet-based controllers controlled via apps, but they aren’t defined by using a two-wire field run in the same way. The two-wire conventional type remains the classic method described by “two wires in its conventional setup.”