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Circulator post purge control

Not to get into it all  i am wondering if there is a way to run my zone  circ post my stat being satisfyed i am using a taco sr403 expandable and would like to purge the rest of the heat out of the system and lower my AWT at the end of the cycle .For a bit more info this is a low to med temp (max 140 at 0 OAT)using panel rads w trv  and staple up the staple up and the rads use just about the same temp and i have a I series valve on the radaint .For a heat source i am using a older munchkin T80M she has been running for about 7 years and no promblems not one code  yet and running at about 96 to 98 eff on the CA for a indirect i am using a buderus st150 and the munchkin is piped using a hydroseperator and has the vision one controls installed , pretty much happy with it's performace even though the munchkin  has  gotten blasted from time to time .Thanks for any help peace and ood luck clammy
R.A. Calmbacher L.L.C. HVAC
NJ Master HVAC Lic.
Mahwah, NJ
Specializing in steam and hydronic heating


  • Zman
    Zman Member Posts: 7,446

    It looks like taco uses a standard cube relay. You should be able to swap it for a delay off relay.

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Zman
    Zman Member Posts: 7,446
    Not sure

    If the cube relay is also controlling the tt call to the boiler it wont work. Check to see if the relay is dpdt (8 pins). If it is it probably won't work. You can always put the time delay relay between  the 503 and the circ.

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Empire_2
    Empire_2 Member Posts: 2,343
    Standard TDR

    ICM makes the time delays for A/C, same can be used for 120vac delay on break.  Takes 2 sec. to connect.  Get the adjustable time dial not fixed so you can choose up to....10 min I think.


    Mike T.
  • Tim Potter
    Tim Potter Member Posts: 272
    ICM part #s ?

    Any suggested ICM part #s for adding 120V post purge pump (Taco 007) control.

    I see some of the units are limited to 1 or 1.5 amp & have voltage drop, not sure if that is too close to the max rating or if the voltage drop matters for the 4 min it will be ronning each cycle.

    Thank you,

    Winter Park, CO & Lenexa, KS
  • CMadatMe
    CMadatMe Member Posts: 3,086
    Just Plug In

    The PC600 Timer Card into the power port of the older Taco EXP Control. The new one already have it standard by selecting the proper dip switches.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
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