Assuming you have it plumbed correctly, this has to differences in the gauges. Either or both gauges could be wrong, IE one cold be reading 1 lb too high, and the other 1 lb too low
it can only be plumed one way. it has a bottom fed inlet and two side mounted oulets. i think it could be the gauges also. either way i ordered new stuff. i just need to find out if its bad. if so then i will pitch it. if its good then i will hang onto it.