I have a central heating system based on PP-R piping and radiators. The PP-R piping goes under the floor. The problem is that the pressure is droping 0.2 atm / week and I am sure there's a leak somewhere under the flooring.

I was wondering if anyone has heard of some sort of sealing substance that could be injected into the system? I've read about something similar for copper piping, but can't find anything related to PP-R, don't know if it would be even possible.

I really don't want to remove the flooring in order to fix this, due to costs, so I am considering this as the ultimate solution.

  • 1
    You still need to find the leak so you know where to inject the compound into.. plus if you dont know where it is, how do you know if you've fixed it, or if there is any other damage requiring repairs?
    – Steven
    Apr 19, 2012 at 15:37
  • Thanks for your feedback. I was thinking of something that would be injected in the whole circuit (except boiler); I've read of something like this for copper pipes. It's a pretty short circuit (55 square meters apartment). I think a pressure test could be relevant to see if the leakage is fixed.
    – Andrei
    Apr 20, 2012 at 7:13

1 Answer 1


As Steven mentioned how do you know you've fixed it? Also, do you want to circulate sealing compound through your boiler?And damp under a house can cause a lot of problems. If you want to know the exact location of the leak and under the floor is totally inaccessible you could consider using a thermal imaging contractor to find the leak to localize damage to the flooring and [this site] (http://www.ekoplastik.com/?download=ekoplastik_ppr_mont_en.pdf) has information on repairing of PP-R pipe in page 27.

  • 1
    Thanks for your answer. It's an apartment. And the leaks isn't big enough to be seen at my neighbour from below. I wasn't thinking to circulate the sealant through the boiler, but rather disconnecting the pipes from the boiler first. I think a pressure test would show if the pipes would be fixed. Right now the pressure gauge from the boiler shows clearly that i have a leakage somewhere. Thanksfor the link, I will be looking into it.
    – Andrei
    Apr 20, 2012 at 7:10

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