I'm currently performing annual maintenance on a CVHE080. I have had trouble in the past pressurizing these machines, so i've isolated both bundles and i'm circulating hot water thru both the condenser AND evaporator. Water temp currently at 130F & (pull out ur P/Ts fellas) & the actual GUAGE pressure reading is approx. 1.5psi. The UCP2 interface sat. evap temp reading is 91F, which is pretty close to my gauge reading. Pressure in the machine right now should be well above what I'm currently seeing. I'm going to eliminate the obvious and tell you that both tube bundles are CLEAN. I've had this same problem with many other Tranes in the past & attributed it the R-123, but I've pressurized many YT's (some well over a 1000 tons) and had no problems. Anyone else ever have this problem on the Trane machines? Any theories as to why?