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Is Kitech safe when used in concrete slab for in floor radiant heat?

Have a home that had Kitech installed in 2008. Major failures in fittings in The domestic water system caused us to replace the entire system. However, Kitech is still residing in the concrete slab inside the in floor radiant heat. From all I have read the failures with Kitech is always at the fittings. Has anyone had specific experience with pipe burst/Fillier inside the concrete slab. In other words could the risks be reduced by simply replacing the fittings and possibly manifold. The only other alternative would be to jackhammer the concrete and rip out all the plumbing.


  • hot_rodhot_rod Posts: 11,468Member
    Unpredictable how much if any of the tube will fail. Some suspected electrolysis at the fitting. Some failures were collapse, some were bubbles between the layers. Perhaps some lasts 100 years without any issues?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • ZmanZman Posts: 4,899Member
    I would be very surprised to see the Kitec tubing fail in an in-slab application.
    Be sure to keep your supply temps nice and low and maintain good water quality.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • IronmanIronman Posts: 5,041Member
    This is just my experience. I have run literally miles and miles of Kitec until it was pulled from the market. I've yet to see a single failure other than a few of their older style fittings weep slightly. I've never seen the tubing fail. I've got it running underground between my wood boiler and the house. I never used it on any thing but hydronics: open loop, closed loop, hot and chilled water.

    I don't see where it would be a problem in slab, but keep in mind that with concrete, "what's done is done". You won't get a second shot at it.

    I would also make sure that you use the new style fittings that employ a SS compression sleeve, not the old style that employ a crimp ring.

    To my knowledge, most of the issues were with it being used in potable water systems that had high chlorine content.
    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • RetrosPexRetrosPex Posts: 54Member
    Kitec: As I stated in a posting of mine a few days ago, I received legal papers from the class action lawsuit. The lawsuit centered on the fittings primarily. They supposedly had too much zinc in them, and it caused corrosion, generally in and around water heater applications. I never had a single problem with mine in 15 eyars or so. But Rod posted some photos of awful split tubing, so obviously it happened.

    I'd pressurize your slab. You can buy a kit to do that for $20, and pump it up by hand. Make sure it isn't leaking. If it isn't, I'd replace the bad fittings, and move on. If you cannot find them, post that info. Someone like myself will help you.

    Good luck.
  • hot_rodhot_rod Posts: 11,468Member
    hmmm, why would you want to install a product that the manufacturer pulled from the market?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • DZoroDZoro Posts: 761Member
    I have seen pipe failures all had one thing in common. Large temperature swings. Too much expansion and contraction, pipes I found were splitting at the aluminum seams. Keep your temperatures as constant as possible, odr will also help.
  • RetrosPexRetrosPex Posts: 54Member
    Kitec, answer to Hot Rod post: I'm not saying I would install it. The OP stated that he has a slab with it already, and wondered if changing the fittings would help, or the manifold. My comments are based on my experience with the tubing and fittings, and all the literature I got from the class action lawsuit. I'm not telling him to do anything.

    That info included some links to a company that makes a line of replacement fittings for the tubing. I looked into them, and they were quite expensive. I have put Kitec in 5 slabs in buildings, and none of them have had any problems. Also, I have not experienced any of the corrosion of fittings either. I would not be afraid to use the tubing in a place where a leak could be discovered, and not do a lot of damage. A slab would certainly not be my choice, knowing what you, and others have pointed out. But, his is already in the slab.

    He mentioned jack-hammering the slab out. I think that my suggestion, to pressurize the slab and check for leaks is a good one. A prudent one, in fact, before he does anything else. I don't know if his fittings failed, for that matter.

    To address the portion of your comment about them being taken off the market: I'm sure you understand that in today's litigious world, many decisions are made by insurance companies. Maybe they couldn't fix the problem. Maybe they wanted to limit their exposure? Who knows?
  • Mark EathertonMark Eatherton Posts: 5,844Member
    I agree with Ironmans experience. No tubing or fitting failures on closed loop heatings systems that are receiving proper water treatment. Biggest problem we experience has been the compression nut backing itself off, causing a leak. We cure that with LocTite Blue.

    As for using it today, Watts took over the Kitec extruders and the exact same PAP is still on the market. I think Kitec crumbled to their lawyers on this one. Not saying that they didn't experience SOME tubing failures, but if you're making a million widgets, you can expect SOME failures. I think the accepted industry standard is 2%. Beyond that is a concern.

    Quite honestly, I don't know a manufacturer that hasn't experience tubing and fitting failures to some degree. It happens. We have adopted a protocal for Kitec in closed loop applications. First thing we do is to direct them to the Kitec class action web site. Second is to explain our experience. Third, if they choose it is to replace the fitting O rings, and used LocTIte blue to remake the compression connection. BTW, I think Watts has gone to the crimp fittings only on this product line.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Sal SantamauraSal Santamaura Posts: 279Member

    ...if you're making a million widgets, you can expect SOME failures. I think the accepted industry standard is 2%. Beyond that is a concern...

    I always loved the anecdote W. Edwards Deming told. It concerned a manufacturer purchasing 'widgets' from a Japanese supplier. When the first batch of 10,000 widgets arrived, it was accompanied by this message:

    "Your purchase agreement specified a defect rate of one in 10,000. We don't know why you want a failed unit, but have included one defective 'widget' in this shipment. It is tagged to ensure you can easily identify the defective sample."

  • RetrosPexRetrosPex Posts: 54Member
    Mark: I want to make sure I understand your comment: are you replacing the o-ring and then adding Loc Tite Blue? Are these in cases where the compression nut has backed off, as you comment? I've never had one back off, or leak. This is really good info to have, because I have a huge amount of those fittings sitting around. I was unaware that Watts picked up this line. Thanks for the info.

    Sal: Great comment! I've done the Deming training, and worked for a Japanese company for many years. I can appreciate the humor in that statement.
  • hot_rodhot_rod Posts: 11,468Member
    I thought Watts PA was made by Rifeing?

    Three separate issues as I recall with Kit. The high zinc content fittings would react with the aluminum barrier and break it down.
    High pressure and or high temperatures seemed to cause delamination, the 180F fin tube systems failed quickly.
    Around here a lot of Kitec was used on OWF installations, those commonly run around boiling temperature :)

    The tube would either bubble out with fluid between the layers, or sometimes collapse internally, a tougher troubleshoot, hard to know how many of internal failures there are out there.

    There has always been an argument between the lap seam, or butt weld seam PAP guys, probably still is.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • RetrosPexRetrosPex Posts: 54Member

    I know you are advocating for people to not take a risk with that tubing, which I certainly understand. I know from the info sent to me that you have nailed the issue on the head regarding the problem with the zinc. There was a lot of buzz at that time that you could usually see the difference in color between the fittings, when they had too much zinc. I don't know if this is true, but I did see numerous fittings that were much lighter in color. However, I have not had a failure.

    If a person was going to use them at low temperature, do you think they would be safe using them in areas where they are accessible? I only ask because I have a whole bunch that I'd like to dispose of, and I want to be able to properly inform interested buyers as to the risk.

  • hot_rodhot_rod Posts: 11,468Member
    Hmmmm, evidence proves that it's pretty much a given that they do fail. How many, how soon, you would need a crystal ball to know.

    My theory is that once the aluminum starts to corrode, whether you see a leak or not, your O2 barrier is being compromised. O2 ingress leads to corrosion the formation of magnetite and all sorts of potential problems with valves, boilers, ECM circulators.

    Just ask the Colorado guys that rehab old rubber tube and non or ineffective barrier tube systems about that, it's an expensive, frustrating problem that will be ongoing for our lifetime.

    Seems like the entry fee to avoid that gamble would be money well spent?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • RetrosPexRetrosPex Posts: 54Member
    Well said. Thank you.
  • Mark EathertonMark Eatherton Posts: 5,844Member
    HR, I'd heard the rumor about Watts getting its extruders from Kitec from a former rep employee, and really don't now how true it is.

    Regarding your dissolviing aluminum theory, possibly. But just like the Onix O2 ingression issue, there IS a parallel path for oxygen to get into the fluid, at every manifold connection. Until someone comes out with an oxygen barrier O ring, there is a definite path for the O2 to get into the fluid stream, and eat anything ferrous.

    We just did replace a bunch of leaking Kitec fittings (for a lawyer worling on the Kitec recall) that required us to cut the tubing back about 6". This was on a system that hadn't received ANY water treatment (worst case scenario) and upon inspection, the aluminum barrier was still intact.

    I'm sure that there are cases out there that go contrary to our findings, but in Denver's water, on closed loop systems, this is what we are seeing.

    I suspect that before we start pushing up daisys that we will see even more failures of tubing (pick a brand and a type) and fittings. Times, they are a changing.

    Retrspex, yes, if it leaks, new O rings and Loctite. If it ain't broken, we don't fix it...

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • CanadaKeithCanadaKeith Posts: 9Member
    Good to read real life comments about Kitec. Here in Canada the lawsuit also names the various IPEX PEX products ( in addition to the PEX AL PEX). This complicates the issue when I raise it as an inspector ( private residential home inspector) , as the PEX product seems to have no rocky history. However I am obliged to warn the client that the insurance companies may react badly if they are aware that one of the named brands ( for example PLumbBetter PEX) is installed in the house. Some insurance companies have responded they are OK with it, others have said they are not OK with it (the PEX ). The true PEX AL PEX Kitec is rare, I have only seen it once and that was in a custom house with in-floor heat and combo forced air units. Has anyone seen a problem with PLumbBetter PEX product from pre 2007?
  • RetrosPexRetrosPex Posts: 54Member
    Mark and Canada Keith:

    Mark: Thank you for the clarification. I have crap loads of Kitec laying around, and crap loads of the fittings. I have never had a failure or even a leak, but I still get what Hot Rod is saying. It is a risk. Based on the info, I've decided how to use up my 1" Kitec: I'm getting ready to build a new garage, and am thinking of a heated drive. I have everything on hand except for the slab foam. To get the proper spacing for the Wirsbo Hepex in the slab, we will fasten the 1" Kitec to the foam, and run Wirsbo over top it. Our drive will end up about 90' so I figure we can run 2 lines down and back with 1" for each loop. Then put in 3/4" Hepex zip tied to it. Leave a loop in the garage, or basement, and if the Kitec ever fails, abandon it. The only drawback I see to this is that a leak would mean antifeeze leaking out, but that goes for any other tubing that could fail too.

    I'm not comfortable selling the Kitec to someone else, so this is a way to use it up. I have 1800' of 1" Kitec.

    Canada Keith: Most of those failures were near water heaters, and high heat. If you shop around, there are other compression fittings that fit Kitec.

    All of this is a risk, however.
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