i work at an apt complex and we have app. 450 goodman hp's and 2 or 3 tranes, so i'm not familiar with them at all. there are only 2 service valves that i can see- high and low side. i'll look at it again today. thanksSounds like you took your readings on the service valve schrader fittings. They should be about the same in heat mode then. Need to use the true suction fitting.