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Stuck open valves on Truflow Manifold

I installed my 13 zone Truflow system with a contractor friend 22 years in the freezing cold...lol. It is paired with a Buderus boiler. The system was NEVER set correctly for zone flow...and has no flow indicators. I honestly think I can get the flows dialed in...as they are now. My issue is flow bypassing closed...actuator down valves to areas that I dont want that heat. I see that I can buy replacement valves and they seem to be relatively easy to get at. My fear is that when I remove the valve for replacement in the off season...I will have to get the system "primed" ie get the introduced air out.  If I cant get it right I am pretty much screwed. My contractor buddy is no more...and I dont have a contractor/plumber interested in even talking about it. I live 25 miles south of Boston. I dont mind doing the valve swaps... but I have nobody to fall back on if I mess it up. Advice on how to do this right would be appreciated...as would an actual contractor as a backup. LOTS of companies love to say they are fluent in this...but have not a clue. I am an appliance repair tech/owner of 35 years and have reasonable skills. I really appreciate this opportunity to get information. Websites and YouTube are VERY limited.  Thanks for any help you can pass along. Roger Whiting.


  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,053
    Are the valves actually defective? (These valves are part of the manifold)
    Could it be that only the actuators are defective?
    You do not need to open the water side to replace the actuators.

    What is the goal? What is the system doing now that you want to change?
    I see that you mentioned that you want to lower the heat in unused rooms. Is that the goal?

    Is everything else working?

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • Alan (California Radiant) Forbes
    I just did this operation yesterday on a house with a 5-loop manifold, but the symptom was different: no flow through some of the loops which is a more common occurrence when the valves are stuck. 
    Luckily, the manifold had shutoff valves and the water loss was negligible when the first valve was removed. What is your situation with valving?

    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
  • hot_rod
    hot_rod Member Posts: 22,251
    Remove the actuator and that port will be 100% open. The valves themself rarely stick closed, the spring is fairly stiff the pushes them open

    With the actuator removed does the pin move down by pushing on it with a metal surface? A hammer face for example?

    Do you have the plastic caps? You could use those to adjust flow until you get the actuators sorted out.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Dave Carpentier
    Dave Carpentier Member Posts: 594
    I found a couple of zones bleeding thru on my 22yr old Uponor manifold.
    I had to snug down the valves a bit, and now it's good.
    If you remove the actuator, you should be able to turn the valve body using one of the black plastic caps.
    Although.. if it hasnt moved for 20+ years, you might start leaking at the body o-ring. I got lucky.
    I didnt turn it down (in, clockwise) much.. maybe an 1/8 to 1/4 turn ?

    30+ yrs in telecom outside plant.
    Currently in building maintenance.