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Hot water showing up in Hydronic airhandler coil, when no heat is called for.

HGR693
HGR693 Member Posts: 3
in THE MAIN WALL
Hello,
Have a SMART tankless (60Gal) unit, boiler fed. Boiler also feeds two hydronic coils for heating the home. My second story coil, has hot water in it, whenever the boiler is running, even though the TACO cir pump is not running. Cast iron fitting at this TACO pump, is reading around 120* while other zone ( first floor) cir fitting is less than 100*. What might be the problem. Thank you

Comments

  • Canucker
    Canucker Member Posts: 722
    Sounds like gravity flow. Are there any check valves in the system?
    You can have it good, fast or cheap. Pick two
    STEVEusaPA
  • HGR693
    HGR693 Member Posts: 3
    not that i know about. There are three Bell & Gossett Flo-Control Valves, coming off the boiler, about 6' off the ground. They have NEVER been checked, in 14 yrs. I know that they are there to prevent gravity flow. Could this one valve, be my problem? Thankx
  • JUGHNE
    JUGHNE Member Posts: 11,279
    I think that could be it. It may be stuck open partially and not seating correctly.
    Most of the Flo-control valves have a manual override, lever or knob. You might exercise that a few times. If still flowing, then perhaps the rubber mallet hammer applied might seat things.
    I would support one side with the left hand and wrack the right side with the hammer. If no mallet then a large rubber handle screwdriver or hammer handle. But never the actual metal hammer head. This secret technique has been applied for many repairs......just don't let the customer see you do it. ;)
    Canucker
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,495
    Agree with @JUGHNE flow control valve is most likely leaking by
  • HGR693
    HGR693 Member Posts: 3
    Awesome!! I'll let you know . I have the Install/Oper/Serv instructions, so it looks like you can clean these things out. I'll prob have to get a rebuild kit or gasket, from supply house to rebuild.
    Thankx
  • JUGHNE
    JUGHNE Member Posts: 11,279
    The manual lever could have been moved part way to manual position. I would sure check that before a full drain down and opening up.

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