I have an oil burner that heats three zones in my home by way of three Taco Zone Valves and single transformer. I am adding a fourth zone, and Taco Zone Valve.
I am going to eliminate the transformer and install a Taco Zone Controller (zvc404 -4) because, as I understand, the transformer will only drive three valves.
How do I wire the Zone Vales using this control unit?
Do I use a three wire Thermostat wire and use all three connections on the Zone valves and wire them to the Zone Valve connections?

 

Please Help
I plan on switching all the controls tomorrow since we will have some warm weather for the day.

 

That is a 4 channel unit with channel 4 priority. You'll leave the zone 4 priority switch in the OFF position. The mode switch gets set to NORMAL.... not reset.

The thermostats connect with two wires to the TT terminals. The wires at the thermostat end will be connected to R and W.

The three wire zone valves get connected with three wires..... 1,2,3 with no wire on terminal 4.

The main end switch contacts will go to the TT terminals on the aquastat.

The newer model of the 404 may have a connection for a third thermostat wire. That would be a C connection if the t'stat required power.

 

I thought that was what I needed to do but I needed to hear it from someone else for my own reassurance.
I wasn't 100% sure because of the wire that presently jumps the #3 terminal on each Zone valve.
I have turned off the priority already because I need the fourth Zone valve.
Wish me luck! It will be near 70 degrees today here near Philly and we are expecting up to 6" of snow on Wednesday.
Crazy weather

 

Just curious how do you heat you domestic hot water?is it tankless or a separate zone? That is a nice control unit,you can also set it up for boiler reset for more efficiency.


Geo

 

I pre-heat an electric 52 gallon water heater with a 60 gallon solar hot water system.
Works very well. I have three women in the house!

 

Well, Everything went well. I did notice something. There doesn't seem to be ANY delay. As soon as the thermostat calls for heat, the boiler fires up. There was a 90 second delay before I installed the ZVC panel.
Do the Zone valves need some time to open??

 

Yes. The zone valves are motorized. On a call for heat.... the motor opens the valve. When the valve gets to the open point the end switch starts the boiler.

Now the controller supplies the end switch command to start the boiler.

 

I made a mistake in the wiring AT the zone valves. I had wired the green to the #3 and the red to the #1 terminal. The boiler came on with no delay but the valves never opened. Makes sense to me now.
Everything is working great now. The thermostat calls for heat and two minutes or so later the zone is active. I have a little bit of air in the system but I can get that out easy enough,
I now have four zone heating system and the basement will be warm enough to watch the Eagles beat the Cowboys after turkey.

 

Thanks for help!
This was my first time on this forum and I appreciate the fast and knowledgeable response.
See you when I start another project.

 

Glad everything worked out. We'll be here.