Have three Lennox systems. A main level piggy back systems with a heat pump in basement and one on an upper level. I have had multiple problems with the upper system. First the coolent seems to continually be leaking out. The company that put it in has constantly come out to refill it. They eventually said it was a something at the condenser fan like a valve or something then after a couple of more times replaced the condenser pump and the coils in the attic. Everything seemed fine but just like before three months later the unit has run out again. This house is a year and a half old and has top of line Lennox systems. I do not know if it is the company that is he licensed Lennox installer here or it is that Lennox is just crap. My guess is I have a leak in the line between the fan outside and the unit in the attic. Unfortunately, that means it is somewhere in the line somewhere in my walls. Can someone give me some guidance on how to proceed to get this finally fixed.