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Moving TruFlow Manifold and Purging Air (several questions)

I'm doing some remodeling and need to move a manifold out while some studs in wall are replaced.
The manifold has what appears to be compression fittings (see photo below). Can these be removed and reused? If not, are there alternate methods of connecting that don't require expensive tools?

Also, these loops are for a ceiling above the manifold. I can't understand how you bleed the air from this system when the ceiling loops are the highest point. Any suggestions or does the pump push the air bubbles out to be released at the manifold.

Any idea why the GPM indicators show around 7.5GPM when the actuators are closed?


  • SWEI
    SWEI Member Posts: 7,356
    The PEX fittings (both inlet and outlets) are ProPEX cold expansion (better than compression IMO.) You can unscrew them using the hex nuts that are nearest to where the PEX joins the brass. If the lengths are going to be the same, you can reattach them when you reassemble.

    If you need to shorten them, you can carefully cut (a hooked carpet knife works well) the outer white band (thicker part) of the PEX, being careful not to cut all the way through the underlying pipe layer. If you nick the brass insert fitting underneath, it will quite likely leak. You could also buy replacement inserts. Either way, you would need the proper expansion tool to re-connect the tubing. It's about a 60 second job.

    If you open one loop at a time 100% and close off all the others, the pump should easily push the air out of the ceiling tubing, even downhill.
  • hot_rod
    hot_rod Member Posts: 22,121
    Looks like glycol in the system? If so you may need a purge pump to fill and purge after you disconnect and replace the manifold.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • stevemac00
    stevemac00 Member Posts: 6
    I need to replace several studs but all have radiant lines like this:
    I can't pull them through with the fittings attached. I may try to cut them out but I'm fearful of nicking the pex which would really be a problem.

    It sounds like I should call an HVAC company to remove and reinstall the pex. I thought the Caleffi Backflow/Autofill valve would fill the system (diluted, of course) and I could purge at the manifold.

    Side note on the glycol: This is because an outbuilding has a Reznor with exposed copper on the same circuit. I'm thinking of asking an HVAC company to put in a pump/expansion tank/plate exchanger so this circuit is isolated and I won't have to have glycol in the home loops.
  • SWEI
    SWEI Member Posts: 7,356
    Before you hire a contractor, make sure they have tooling for Uponor/Wirsbo.
  • RobG
    RobG Member Posts: 1,850
    edited April 2015
    I have an expanding tool that I would be happy to get rid of, cheap! PM me if you're interested.

    And when you replace those studs drill the holes larger to reduce friction on the pipes.
  • stevemac00
    stevemac00 Member Posts: 6

    For reference, in this photo, the Caleffi HydroLink is installed upside down (for convenience to boiler which is to the right). This goes to the upstairs manifold shown above. I'm going to move the manifold and route/replace the return/supply lines to accommodate a bath remodel.

    I ordered a ProPex expansion tool as I decided to also use that instead of crimps for the aquapex plumbing.

    Is the pump installed on the supply?

    What is the valve/spigot for on the other end of the loop? Is that for purging air from the return?