Hi guys, hopefully you can help me out. I have a 15 year old Water Furnace unit, Model ATV034A11OCRT and closed loop system.Methanol. I also added about 2 years ago a QT Flow Center.(i think) Its been good over the years and I have only replace a few parts here and there in that time. Just recently it quit making heat and in the heat mode will not warm up the house. The outside temps have warmed up some and now it will not cool either. It just runs and runs with no effect on the house temp. I had a Tech come out and check things out and he says he doesn't know what to do other than replace the entire unti with new. I can't believe that some components can't be replaced to get it up and running correctly again. The Tech checked everything he knew to check. Pumps are all running, compressor pressure seems okay. Loop temp in was 37 degree's F out was 33 deree's F. What are your suggestions??? Oh, and there are NO faults showing.