Hey folks, have a look and give me your thoughts...low pressures on tandem scrolls

[hands]

When you are checking operation of the circuit you changed the compressors on, is the other circuit also running. You said before that the evaporators are one atop of the other. If you only have one circuit running, the air flow will tend to flow more through the dry coil than the wet coil that is cooling. This will lower the evaporator pressure.

[B_roche]

Is it a mcquay?

Sent from my MZ601 using Tapatalk

[slctech]

Also, may need to calculate additional charge if you upgraded to new possibly larger LLF or SLFs.
But definitely want to get some head pressure controls and if not already, crank-case heaters.

[Thaaguy]

This is a York unit. The evaps are staggered (to balance flow I am guessing) - one is about 10 inches behind the other and a foot higher...like building an evaporator staircase if that helps at all...

I've only run one stage at a time.

That's a good point about the drier, the new one is much larger...perhaps 3 times the size of the old one. Thanks!