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Heat in baseboard zone turned off

Have a relatively small 2 zone water baseboard system, 1st flr/2nd flr with tankless.  I'm getting what I believe to be migration or "ghost " flow, whatever the correct term, to the 2nd flr zone with tstat turned off.  Circ for each zone followed immediately by flochek. No other flow controls. Just a bad check valve or could a different piping configuration help this?  Can checks be too close to circs? Any reason not to add spring checks on both sides of each zone?  This seems an easy fix but if there is a more "correct" solution I don't want to overlook it. Thanks for reading 

First pic is return. 2nd flr is black circ.


  • Ironman
    Ironman Member Posts: 7,399
    Adding another check in the return may solve it, but you need to get those circulators mounted horizontally. They are water lubricated and you’ll burn up the back bearing like that.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • yellowdog
    yellowdog Member Posts: 159
    after correcting the mounting of your circs, i would open up the checks, clean them and see if they are working correctly.