Grundfos UPZCP-3, 3-Zone Pump Control - Set-up?

Hydronicolic

I have a 2-zone RFH system being heated with a Tankless Heater. I have the 3-Zone Pump control set-up with the Tankless pump on the 3rd zone relay. I wired the End-switch terminal over to the TT terminal on the 3rd relay thinking, on a call for heat, the end-switch will make and start the Tankless pump. When ALL calls are satisfied, the End-switch opens and the Tankless pump shuts off. What is happening: it works on the start-up, but when ALL zones are satisfied, the End-switch doesn't open unless I kill power to the Control, leaving the Tankless pump running continuously. THE QUESTION: Is there a way to make this work?

hot_rod

A single pump system? Does the tankless supply DHW also? Or just dedicated to heat?

Hydronicolic

Dedicated.

Hydronicolic

I've used a separate single zone relay in the past but thought, "what the heck" save the cost and labor of the 2nd control.

I was wondering if tying in a resistor between the E.S. and the 3rd Zone relay TT might create enough load to make this go away, while realizing I'm not an electrical engineer.

hot_rod

If you are trying to control 3 circulators a ZVR?

\The ZSR is the control for switching circulators Zone Switching Relay

The ZVR Zone Valve Relay is a 24V relay for powering zone valves.

There may be a work around

You have 2 zone pumps and a boiler primary circ that needs to run with either zone circ?

Hydronicolic

That is correct. 2 Zone pumps, and 1 Heater pump on the 3rd Zone relay contacts.

Alan (California Radiant) Forbes

Wire your primary pump to the "Primary Pump" terminals with all the dip switches in the off position. Remove the wires from the end switch to zone 3 TT terminals.

DYI

I see a problem with the vent pipe connection to the Takagi boiler. The installation manual says the vent pipe must be inserted inside the collar, not outside. This is to ensure that a leak-free seal can be made with the o-ring inside the collar.


Here's what my last Takagi install looks like.

Hydronicolic

Good eye! That was "By others". It was originally vented with galvanized. I called that one and the plumber friend came back and screwed it up more professionally.