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

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Hydronicolic
Hydronicolic Member Posts: 16
in Thermostats and Controls
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?

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  • hot_rod
    hot_rod Member Posts: 22,143
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    A single pump system? Does the tankless supply DHW also? Or just dedicated to heat?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Hydronicolic
    Hydronicolic Member Posts: 16
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    Dedicated.
  • Hydronicolic
    Hydronicolic Member Posts: 16
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    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
    hot_rod Member Posts: 22,143
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    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?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Hydronicolic
    Hydronicolic Member Posts: 16
    edited March 2020
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    That is correct. 2 Zone pumps, and 1 Heater pump on the 3rd Zone relay contacts.
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,002
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    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.


    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • DYI
    DYI Member Posts: 12
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    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
    Hydronicolic Member Posts: 16
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    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.
    Alan (California Radiant) ForbesCanucker

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