replacing wirsbo a3080404 zone control panel has 4 wire zone valve conn.
has 3 wire thermostat connector with 4 wire thermostats
tried taco zvc-405-3 but thermostat conn. only have 2 wire conn.
and 4wire zone valve conn is there a taco box or another box that will work
You probably have the Wirsbo 4-wire thermostats like the 501. Two of the wires are for 24volt power and two are for the endswitch.
In order to make this work on the ZVC controller, there should be a terminal on the top left of the ZVC board labeled 24 volt and common. Use this terminal to power up all of the thermostats, and the endswitch wires will go to the corresponding stat location.