Many radiant heated floor systems have been shut down because of small line leaks that can't be found or fixed. Home owners can then be faced with the cost and installation of a partial or whole new hvac system. If a hole[s] develops in one of the lines, it can be a radiant floor disaster. If you can find a company that is willing to try and fix a radiant floor leak, the demolition of finished floors and concrete, plus the cost, is incredible and may not always prove satisfactory. However, there is simple solution using GEOLOOP LEAK SEAL that is usually effective, and may be worth your while. Method: Try to isolate the line with the leak and use an external sump pump and no less than a five gallon container. Allow the water to circulate through the line and monitor the water level drop in the container. This will allow you to determine the water loss. If not too severe add the GEOLOOP LEAK SEAL to the container, after following mixing instructions, and allow the solution to re-circulate through the loop. If and when the level holds, you know you have stopped the leak. Continue to re-circulate for an additional 2-3 hours. Clear the line with air and let it set for 48 hours. You can then pressure test the line between 10-20 psi. If the pressure holds re-add your water, add the heat and pressure up to 15-20 psi. In most cases, this method will work 80-85% of the time. You now should have a leak repair lasting for many years. If this method is not effective in your circumstance, a manual repair would be required.