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Replacing old Manifold & pb tubing

Riko Member Posts: 3
edited March 2017 in THE MAIN WALL
I have a 25-year old Infloor system, with polyb tubing, leaking at the manifold (12 zone), tubing imbeded in cement when home was built. Love the radiant heat, but concerned about life of pb. Live in the boonies, in No. California, and have had a hard time finding someone to even look at the system. Finally found a highly recommended one who did check the system and gave a bid: replacing manifold, using compression fittings to connect new tubing from the manifold with old pb tubing running to water heater. I'd like to keep 12 zones, but most manifolds today seem to be less - any comments on the 12-zone Rifeng? Or the advisability of trying to "fix" such an old system, given today's more modern materials. (I'm a recent widow, elderly, but still able to think and reason - husband was an engineer, and some of his thinking rubbed off on me ...). Thanks for any thoughts, particularly on old systems and their longevity.

March 8 2017 - update: Thanks to all for help and suggestions - either Bob or Alan recommended I call Bay Hydronic - immediate response. After sending pics and talking, reasonable contract signed, and Alan came out - very knowledgeable and professional. He worked 6 straight hours installing manifold and pex tubing - I have warm floors and home again. (of course, unseasonably warm weather also arrived - oh well.) AMEN - thank you Bay Hydronic.


    JUGHNE Member Posts: 10,905
    I put PB tubing in our house (most buried in concrete ) in 1994.
    The only problem has been the connections at the manifold.
    Our tubing is 1/2" Outside diameter--3/8" inside. It is actually called PBX, it has an oxygen barrier built into the tubing.

    If your tubing does not have the O2 barrier there is chance that ferrous piping, pumps, cast iron boiler could be affected. It is suggested to use a heat exchanger to lessen this happing.
    If you have not had any problems with say a cast iron pump or boiler in that length of time then not to worry.

    I had to replace a manifold and used push in "quick" connectors to transition from 1/2" OD PBX to 5/8" OD PEX. I searched at length for a compression fitting for this purpose and found none.
  • hot_rod
    hot_rod Member Posts: 20,790
    The tubing should be fine if it is holding pressure. If it heats comfortably and inexpensively, stick with it.

    There are crimp fitting available to transition from the poly b to pex. I found these online with a google search.
    Transition to pex then you have all sorts of manifold options and price range.

    Not much of that poly b had oxygen barrier, so all non ferrous parts should be used. Pumps, expansion tanks, etc.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • kcopp
    kcopp Member Posts: 4,305
    edited January 2017
    Watch out some of those manifolds. They stick a lot of "bells and whistles" on & they and they end up adding a lot of restriction...then you will have flow issues.
    I really like the Sioux Chief manifolds. All copper. Very simple. I agree that the tubing will hold up fine. The only time I really see PB tubing break down is if there a high levels of chlorine in the water.
    Do you have any pix of the system?
  • Riko
    Riko Member Posts: 3
    Thanks for the suggestion kcopp - Here's the manifold with current pipes:
  • Ironman
    Ironman Member Posts: 7,223
    Stay away from that, and any other Chinese manifolds. Caleffi, Rehau, Viega, Uponor are good ones.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    Solid_Fuel_ManDan Foley
  • We installed many of those Infloor manifolds over the years and many of them are starting to leak.

    The biggest problem with replacing the manifold is the size. The newer manifolds are much larger and you often have to modify the wood framing to accept the new manifold.

    Your pb tubing should be fine.

    Ironman and kcopp make good suggestions for manifold manufacturers.

    I'm in Berkeley. If you need any advice, give me a call at (510)773-9870.

    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: 20,790
    There are plenty of good radiant guys in No Cal. If it is out of Alan's range, let me know, maybe I can steer you to another.

    That entire assembly needs an upgrade. A new manifold with actuators could really clean up that space.

    The manifold could mount up high and extend the lines up to it.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Riko
    Riko Member Posts: 3
    Thanks to all for your comments - I have not been able to respond since first posting this,. I will try to post a pic of the manifold here - the rest of the system is down with the water heater in basement, see 2nd pic. Alan and Bob, I will be contacting you tmw.
  • Zman
    Zman Member Posts: 7,495
    edited February 2017
    Yes, that is a late 80's early 90's vintage "Infloor" brand manifold. They do one this well and unfortunately, that is they leak, sometimes if you just look at them.
    The tubing is PB without the o2 barrier which would account for the failing steel expansion tank.
    Unless the tubing lengths are way different, you could just replace it with a simple copper manifold. Most manifolds can be extended to get you your 12 loops.
    The fittings that hot rod suggested are the key to making the transition from pb to pex.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein