taco zvc 404 with erie zone valves

k haynes_2

can someone lend a hand with this problem rewired a boiler has a brand new honeywell digital aquastat one of the universal series im sure you know what im talking about. a brand new taco zvc 404 switching relay, and erie 4 wire zone valves. also has a seperate aquastat for the indirect tank with its own zone valve. here is the problem, the indirect zone is working fine when activated pump is engaged and the burner starts until call for heat is satisfied. the other two erie valves will open on a call for heat but neither will engage the pump or start the burner. my end switch is attached to tt on the aquastat from the zvc. the second end switch isnt hooked up right now and the circulator is running off the dry contacts no and com. do i need to to hook up the end switch b on the zvc to the pump and how do i do this? i was figuring that it is a problem with the zone end switches , and as i dont have a lot of experince with erie zone valves i figured i would ask here. how do i get this to work when there is a call for heat to have all the zones engage the pump and start the burner. the indirect tank as stated has its own aquastat and is powered 24 volt and works fine. dont have any erie wiring info and want to get this running right

thanks in advance

Eric_32

wiring help

Hi, will do my very to help, have wired many many taco controls, one question. Are u running a separate pump for the domestic or 1 for all.

Jim_64

Here is a copy of

of the Taco wiring guide.The end switches do nothing on a 4 wire zone valve w/ a ZVC.

Eric_32

wiring help

If you are using 1-pump for all heat and hot water:
The circulator needs to get power thru the 2nd end switch.

There is no power there,it is only a switch that closes when any zone calls even priority. Just like the burner closing. So will the pump. Add a jumper from your hot leg powering the transformers in the multi box to one side of the 2nd end switch. the other side of the end switch will be the hot leg for the circulator pump.

Remove all wires off the Zone 6-relay terminals. They are used if you are using a 2nd pump for the domestic. In that case u run a hot leg to zone 6 com. DHW pump feeds from the Zone 6 N/O, and the Zone 6 N/C powers that 2nd end switch which powers the heat pump. When Priority is running N/C is open which kills the Heat pump. good luck

k haynes_2

running one pump for domestic and heat

k haynes_2

running one pump for both domestic and heat. by using the second end switch will this allow the burner to also fire as this is a cold start setup im just stumped why does it work the way it is wired now with the dhw which is on a seperate aquastat and the heat zones currently wont fire the boiler. as stated the first end switch on the zvc is connected to tt on the boiler aquastat. tom im going to wire the second endswitch in to the circulator and disconnect the current setup my question is the boiler going to start? thanks for any help.

Eric_32

end switches

Hi,
Both end switches should close when any zone calls. Check with a continuity tester to see if the end switch is closed, maybe something else not right. This will definately solve the circulator not running. If both lights are on for any particular zone, then both end switchs should be closed. if it doesn't turn on the boiler, try jumping the end switch terminals that the boiler aquastat TT are attached to , it should fire the boiler as long as the boiler is below the Hi-limit setting on the aquastat. Good luck, let us know how you make out

Eric_32

If tom. you still can't get the boiler to fire wired this way, give Taco Tech guys a call, the number should be in the paperwork with the ZVC. They are the best at diagnosing their products and will find quickly if there is someting wrong with their box.

Joe Mattiello

Apparantly, the endswitch on the zonevalves is not working, or you do not have an end switch at all. The 3, and 4 terminals are looking for an endswitch closure to pull in the main endswitch, and extra endswitch. to circumvent the need for en endswitch on the zonevalve, place a jumper between the 3, and 4 terminals to simulate an endswitch closure. This should remidy the problem. Additionally, you can energize the extra endswitch with 120 volts to run a system pump, or use the C1, C2 terminals on the boiler aquastat; either way will work. If you have a seperate DHW pump, you can use the NO/NC terminals with the extra endswitch to break the 120 volt supply to the COM terminal.