Wiring zone valves

[trumpeterb]

I am wiring my radiant system in now and I have a question about wiring the zone valves.
The taco valves will be connected to a taco zone valve controller box. On the valves there
are 4 ports for wires. Two are marked 24V and the others are marked end switch. I am running
18/2 wire from the control box and need to know which ports on the valves to connect the wires.
There is an "end switch" port on the control box to which the circulator is connected, so I assume
that the end switch ports on the valves are not going to be used..

 

[sgschwend]

I believe what you have is a switch on the valve so that the valve position can be detected by the "controller". You have a 24V valve which is the other two wires, no polarity. You will need to run four wires to utilize the full features of the valve.

I believe you will find an explanation of how the four port valves are use at the beginning of the boiler room, in a quick summary the valve when open will close the switch and this closures is used to signal the circulator pump to run.

 

[trumpeterb]

Thanks for that explanation. I looked and I do believe you are exactly right. Here is another question...I have two pumps in the system...one is the primary pump on the main loop and controlled by the boiler control panel, and the second is on the secondary heating loop. It should be controlled by the zone control box just like the valves. I can't figure out where to wire the pump into the control box. There are "dry" ports listed as well as "end switch" ports. I tried the end switch ports but couldn't get the pump to work. Any ideas?

Andy

 

[sgschwend]

Send me you controller brand name and part number and I will look it up on the INTERNET, to see how it is done with that controller.

In the simplified design a 24VAC transformer was added to the thermostat circuit. The thermostat could then switch the 24 VAC signal, which was used to controls a relay to run the pump.

 

[trumpeterb]

It is a taco 405 controller

 

[sgschwend]

Connect the pump between the N/O terminal (3rd terminal from the left) the one that is just to the right of the "end switch", and the neutral (white wire) that comes outl next to the two transformers. You will notice that the N/O terminal connections are larger than the others.

You can see the wiring diagram on page 29 of this document:
(broken link removed to http://www.taco-hvac.com/en/products/Zone) Controls/products.html?current_category=138#