How would I find a punctured hot water line in a cement garage floor heating system?

Karen O
by Karen O
The hot water baseboard system to the house was powered by a coal boiler, but now is converted to electric, with the coal as backup, if needed. The garage floor has never been heated by the heated water pipes as it was punctured early in the pouring of the cement, many years ago. Before we go to the expense of adding a heater to the garage, I'd like to explore ways of finding the location of the leak and then cutting into the cement and fixing it. (The water source has been shut off, of course.) Would a mechanic's stethoscope work once the water was running?
  4 answers
  • Normally to find a leak like that, we use an IR thermometer to scan the floor to see where it has more heat when you have hot water running thru it. A less accurate DIY version of the same idea is to mop the floor wet while hot water is running thru the lines. The hot spot from the leaking hot water will dry the surface faster there. Is there any cheap way to get some hot water hooked up to pump thru that underslab line?
  • Karen O Karen O on Jan 19, 2012
    Thanks for the answer. That gives me 2 ideas to work on. What is an IR thermometer? Is that Infrared? Can only plumbers us the IR? The hot water valve to that line is shut off, now. That may be the first solution to try.
  • KMS Woodworks KMS Woodworks on Jan 19, 2012
    I have a basic handheld "temp gun" that I picked up at HD for 40 bucks or so...the higher end stuff is often called a thermal imaging camera..these can cost upwards of 5 to 20K. Some home energy audit companys will have these...you might be able to hook up with one of those outfits.
  • You need to use a thermal imaging camera. IR guns will not be able to locate this as closely as Infrared camera can. However this is not something you can just rent or purchase as the cameras even cheep ones start around $700 and go up. To find someone who does this you can call local home inspectors in the area as some are starting to use this equipment. Or contact a home energy audit company as many use this equipment when doing energy audits. I doubt plumbers carry this expensive equipment but that would be the last call I would make. The thermal camera will show the location very clearly and is the best method of finding a leak. If you have no luck in finding anyone, email me through my profile and I will provide you with some people who do this in your area.