I have in-floor, boiler generated, radiant heat, and have developed a leak, location unkown, other than it is somewhere under the lower-level (basement) concrete. The system is 20+ years old, and the in-floor heat conductor is a molded black rubber hose material which consists of two hoses which run in parallel and are connected by a flat piece of rubber, forming a ribbon-looking material which is about 1.5″ wide. I estimate that the hose is about 1/4″ inside diameter.
I am most interested in advice on the subject of repairing the leak. Are there “leak-stop products out there that will work?