View Full Version : underfloor heating leaks

23-07-2013, 12:39 PM
Has anyone ever have any luck finding underfloor glycol leaks. I have a customer that has a section of freezer with 7 continuous poly tubing runs of approx. 800' each. 5 of the 7 do not hold pressure and are isolated. thanks for any input.

23-07-2013, 01:52 PM
Here are a couple of options to help you locate the leaks.

article: http://www.uesystems.com/new/wp-content/uploads/2012/07/repradht.pdf



Pinpointing the leak is the hardest part. Once found, you need to break concrete. After the leak is repaired you need to maintain the gylcol.


23-07-2013, 06:39 PM
Thank you for the info, I have successfuly used both of those methods with hydronic heating in the past. My concern is the thicker concrete and insulation of the freezer floor will not allow these methods to be effective. And The water treatment rep I use said the degraded glycol should not hurt the plastic tubing. Thanks again.

23-07-2013, 11:31 PM
I use thermal imaging quite often. AFAIK, it is the only real way to find a leak. Why would the glycol have been degraded? It is not under much thermal stress.

24-07-2013, 04:06 AM
It should not be, I was addressing one of the links from above. I am not familiar with AFAIK.

25-07-2013, 12:29 PM
AFAIK= "as Far as I know". I must be spending too much time with the young texting folk

25-07-2013, 01:40 PM
The gylcol may be be graded if exposed to air over a long time period. Of course I am assuming that the expansion tank is open to atmosphere with a lid. If you have a closed system with a bladder style tank it is much more unlikely that the gylcol will be de-graded.


27-07-2013, 05:56 AM
In a freezer, removing the concrete isn't an option, that's rebuilding the whole freezer.
What are the dimensions of the freezer?
I think there's more happening than just a leak. It's strange you hav so much leaks. I think the whole underfloor is moving somewhere and made the punctures.
Refilling each time is also not an option because you will flush away the underfloor.
Are the tubings burried in the concrete of the underfloor or in teh sand under the isolation?

27-07-2013, 06:03 AM
Why not blowing hot air in it at regular times? Of course, you will have with air almost no mass flow through the tubes.
Or http://www.fixaleak.com/geodirections.html

30-08-2013, 09:59 AM
I tried a thermal camera with no luck. I actually tried to follow the tubing from the header manifold, above the floor down into the floor and lost the image within a few inches. owner wants to next try ultrasonic testing with high flow compressed air. we will see how that turns out. the fix-a-leak may work, but one circuit loses approx. 200 gallons an hour based on static pressure loss calculations, and may be cut, as we now have found the polt tubing is in concrete, not sand. thanks for all the info.. I'll post more findings.

30-08-2013, 10:02 AM
Sorry, Poly tubing, not polt tubing.

31-08-2013, 11:53 PM
Poly.......what? Ethlyene, Butylene?