“Residential Radiant System has been operating for 13 years. They system has 10 zones, two of which are outside loops. The system has never flushed, water chemistry never tested, and make-up water was setup from their private well. Upon testing boiler water chemistry, no antifreeze was detected. After draining and cleaning the system, installed an antifreeze holding tank, constant pressure demand pump and a B911, 1/2" Bronze Combination Fill Valve & Backflow Preventer, System is now running like new with great heat transfer and the correct antifreeze protection plus a make-up system to add antifreeze instead of well water which creates water chemistry issues.”