Have concrete slabs heated with an HTP boiler. 4 manifolds (2 supply, 2 return w/shutoffs). Had a loss of pressure and low water pressure error on boiler. I have isolated the leaks off the manifolds. Yeah, more than one. They are running city water through this to heat the concrete at a car wash in the hand bays. No no.

Question: Is there anyway to fix those leaks? They're running underground through hose...looks half inch. Thx

  • Hoses coming off the manifolds that run underground. Sorry brother
    – Chad
    Jan 20, 2019 at 13:07
  • What is the material of the piping through which the hot water (steam?) is being circulated? What is the temperature of the water/steam going through the piping? Jan 20, 2019 at 13:09
  • I will check as to what type of piping it is and comment back or edit this. Sorry, haven't been able to further look at it yet. Heck, temps can reach well over a few hundred I believe.
    – Chad
    Jan 20, 2019 at 22:31
  • Control of steam at a pressure of e.g. 50 psig and temperature of 300 F is not something for a DIYer. I would imagine that these are steel or cast iron pipes. If they are corroded through, then this would require a serious professional intervention to remedy. Jan 21, 2019 at 4:18
  • I would think that the 50 psig steam from the boiler would pass through a heat exchanger to heat water (or water antifreeze) in a separate un-pressurized loop which would be circulated through piping ("hoses"?) in or under concrete. The temperature of the water in the piping in the concrete should not be much over what the concrete is intended to be warmed to, so maybe about 80 F. It is hard for me to believe that live steam at 300 F would be circulated through pipes embedded in concrete. Jan 21, 2019 at 5:38

1 Answer 1


There are sealing systems for pinhole leaks in copper water piping water under slabs. The pipe is sandblasted or media-blasted in place and then coated in place with epoxy. This may or may not work for the high temperature water or steam you are using here.

  • Its polyethylene line.
    – Chad
    Jan 28, 2019 at 20:21
  • So the lines embedded in the concrete are polyethylene? But you said you have a high pressure/temperature boiler making "live steam", right? So the steam is the heat source in an exchanger. If the boiler pressure is below what it should be, the leak is in the steam piping. Jan 29, 2019 at 1:33
  • No. We have a boiler from HTP. It heats water and supplies it through the poly lines. The lines are broke under the concrete.
    – Chad
    Jan 29, 2019 at 21:49
  • What is the abbrev "HTP"? Jan 30, 2019 at 0:55
  • Right. I don't think there is a repair; rather, I believe it must be tore up and replaced. Initial instal and they did not take into consideration the slope of the concrete. They just set the hoses at one consistent depth and poured. If that is the case, mistakes happen. Needs tore up anyway. I pray to the lord...God willing I'm part of that project. HTProducts., is the name of the manufacturing company that sells the units. Sorry, I should of added that.
    – Chad
    Jan 30, 2019 at 1:56

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