Wiring Vito 100 with Taco ZVC 404 and DHW Pump

MacPHJr

My electrician is on vacation and it looks like I will be have to temporarily wire our new install. Here are the basics: one Vito 100 WB35, three Tac Erie zone valves, one Grundfos Alpha Pump, and one Grundfos 15-58 3 speed pump for the Indirect water heater.



The boiler pump will get wired directly to the power pump module on the Vito 100.The Alpha will have a grounded outlet. The zone valves will be wired to a Taco ZVC 404 exp. Here is my questions, can I wire my DHW pump to the zone valve controller? Can it be set up with priority? Can the two end switches be wired to send separate signals to the RT and the DT on the Vito 100 so that the it will bypass the outdoor reset control and go into high fire for domestic hot water production?

CMadatMe

No

I believe you can if you add the PC-600 card also need to wire the Alpha as a system pump on the zone control. I zone my tanks with a zone valve and use the card on the Vitodens. I never tried it with a circ but should operate the same way.

As an FYI. The pump output on the boiler will run 2 pumps. I wire my zone valves like normal, plug in the card, send XX from the card to DHW and XX from the control to RT. Priority once the card is engaged goes to the card. Heating zones are blocked, boiler goes into high fire and both my boiler and system pump run. Card also gives me the ability to post purge to my tank. I'm not a believer in zoning a tank with a pump. Don't think a few feet of pipe is going to impact my flow rate.



http://www.taco-hvac.com/uploads/FileLibrary/102-094.pdf

MacPHJr

Vito 100 power pump module

How do you wire two pumps into the pump module of the Vito 100? I dont remember seeing two sets of 120v pump contacts.



Why do I have to wire the Alpha to a pump relay? Arent they designed to have constant power and shut-off when it senses that all zone valves have closed.



We like using separate pumps for our DHW. If a pump goes down, at the very least the customer can take a hot shower while we try to get there.

CMadatMe

Amps

The "Pump" contact you see can handle the amp draw. I just pigtail boiler and sytem pump. Zone valve calls both pumps run, Zone valves close pumps stop. Stopped using Alphas and went to Taco VDT pumps. Systems seem to perform better. Bumblebee is just around the corner and can't wait. Delta-t pump with a ecm motor..



When there is a call for heat and power has been sent to the Alpha pump, the Alpha will remember and restart from the last duty point and hydraulic mode.

R Mannino

I Use A Zone Valve

for the indirect and wire the boiler circ and the system circ together. The end switch for the DHW zone valve goes to DHW on the boiler, the rest to RT. If you want priority use a RIB relay to interrupt the other zone valves or a zone panel with priority. I'm not a big fan of extra circulators but if you really want to, use a RIB relay as an end switch on that circ to make the DHW terminals on the boiler. You'll still have the issue of no priority but I haven't found that to be a problem with the 100.

icesailor

Vitodens100 Wiring:

I have a copy of a drawing from Kevin Flynn to Lennie DiPasqua at Plumbers; Supply Co that covers this. I used it on one I did and other electricians use it also.

As I remember, I used the internal pump relay for the primary pump, a 501 switching relay and a SR 404 switching relay or a ZV 404 zone valve controller.

I'm sure that Kevin would either fax or E-mail the drawing if it would help.

Hope this helps.

CMadatMe

Multiple relays

Are not necessay. He has the EXP zone control, the PC600 card works like a champ and gives you the extra end switch to go to DHW to get the boiler into high fire. In all honesty you don't even need a switching relay when zoning valves. Piggy both pumps to pump, bring zv end switches on the heat side to RT and the end switch from the DHW zv to DHW on the boiler. Boiler blocks RT on a DHW call and will go into high fire.

This is an older piping diagram I did..There is an error. Supply and return off the boiler are reversed. I'm only posting it because I wrote in the wiring detail for Taco and Zone Valves..

icesailor

Vitodens 100 Piping:

Are you saying that you drew the primary flow backwards or that the return is on the right and not on the left as you have drawn it?

The primary boiler flow is correct.

CMadatMe

Opposite

Piping is correct if the supply was on the right and return on the left. Flow is correct.