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Uponor TruFlow Jr. manifold: stuck valve

cooper185
cooper185 Member Posts: 31
The A3023522 thermal actuator (mounted on the return manifold) on the stuck zone 4 does open. The picture shows (drop top down)  open actuators on zones 1, 3, and 4. I've lightly tapped the base of the actuator and corresponding manifold area where the return pex line is attached with a hammer and 3/8" flat chisel. The Taco ZVC 406 valve control module's indicator lights show both thermostat and valve working. The system has been working (with several repairs) since 2008. I need advice on how to get some flow through that one stuck valve please.
Life is a river, changing at the blink of an eye.

Comments

  • hot_rod
    hot_rod Member Posts: 21,866
    If you unscrew the actuator it should go full

    Open, the pin should pop up in the valve assembly. If not,sometimes some WD 40 and loosen the plastic packing will free them
    up. If not disassemble and clean the assembly or replace it

    If it is scaled up from hard water, others may follow.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    cooper185
  • cooper185
    cooper185 Member Posts: 31
    Took the actuator off and gave the valve pin a shot of PB penetrating catalyst. The thing wouldn't budge, even after  working with it for nearly an hour. Then I tried pulling it with a pair of pliers. No dice. Then, with some vise grips the pin pulled all the way out, with a resultant steady small leak. Immediately, I shoved the pin back in, and the leak stopped. The other valve pins are fairly easy to open, pushing in almost 1/8" with a thumb, and springing themselves back easily. The troublesome valve pin does not spring back, keeping the valve closed. It is also very hard (have to use pliers) to push in, moving only about 1/16". I've left it open that 1/16", and have removed the actuator so it will not be pushed in. So, that valve will always be open, and that zone will have heated water whenever ANY other zone calls for space heating. A poor man's solution for these 15°F Denver nights. I plan to leave it this way possibly for years to come, or at least when summer arrives, since it will be a major PITA to fix.
    Life is a river, changing at the blink of an eye.
  • cooper185
    cooper185 Member Posts: 31
    I have no idea about a single replacement valve assembly. I'll look into it though. I hope I'm wrong thinking the the whole five-valve return manifold would need replacing. With no floor drain, the bad thing either way is having to drain at least one zone, or perhaps all of them.

    I also hope that the bare valve, without the thermal actuator attached, won't spring a leak with the pin popping out. It didn't leak while running through a complete space heating cycle, supply starting at 70°F and reaching 154°F. The return reached 140°F. No other zones were open.
    Life is a river, changing at the blink of an eye.
  • hot_rod
    hot_rod Member Posts: 21,866
    Disconnect the power from the actuator that you have removed. They can push themselves apart if they are powered and have nothing to push against and limit their travel.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    cooper185
  • cooper185
    cooper185 Member Posts: 31
    Thanks!! Much better advice than permanently setting the thermostat as low as possible. 2yrs. ago those actuators cost $63 apiece. I'm not worried about that valve pin popping out. With careful measuring, I put an old (disconnected from electrical) motorized actuator that should just be touching the pin without closing the valve. My wife is happy with a warm bedroom again.  :)
    Life is a river, changing at the blink of an eye.
  • hot_rod
    hot_rod Member Posts: 21,866
    The white caps on the other manifold can be used to regulate flow if you want to adjust the loop with the actuator removed. Find the correct one first :)
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    cooper185
  • cooper185
    cooper185 Member Posts: 31
    Bob "hot rod" Rohr,
    Amazed am I at the plethora of professional commentaty help you've given and continue to give on so many threads, while you work and give q&a symposiums for Caleffi NA, like your recent Dec. 16th talk. You're an old guy like me to boot. Thank you, thank you, thank you, for your dedication and time from this DIYourselfer.

    namaste
    Life is a river, changing at the blink of an eye.
  • cooper185
    cooper185 Member Posts: 31
    Oh, adjusting the flow regulation of my 'always open' loop consists solely from feedback from my hand, feeling if the baseboard is warm. Of course, calculating pressure drops 13yrs. ago, and equivalently sizing the length of my five loops is reassuring.  Plus there's a little help from my Oventrop differential  pressure bypass valve. Besides the inestimable value of contributors (like "hot rod" Rohr) on this website.
    Life is a river, changing at the blink of an eye.