I have a tacozvc-404-2 and trying to wire uponer two wire zone valves. my problem is that the zone valves open fire when t stat is calling but zone controll box dosent see that there open also how do you wire the circ pump to fire when zone is calling
Install a jumper across terminals 3 and 4 of the zones you have thermostats connected to. Wire 120 volt hot to one side of end switch, other side of end switch to pump. Neutral wire goes directly to pump. Set mode switch to normal. Priority switch to off. That should get you going.
The zvc404 is the facilitator for the multiple thermostats, and corresponding zone valves. When the thermostat closes, TT close to energize the zone valve. The end switch from the valve when wired to the 3, and 4 terminals communicates to the control the valve is open it's OK to fire the boiler and energize the system pump. The system pump can be wired to the extra end switch. the wiring schematic is found on the instruction sheet about midway down on the left hand side. Hopefully this helps.