I just installed a Goodman 3 ton unit in w/ piston that it came with. The low press is 120# and the high side is 335#.

Pressures sound good. W hat is td across inside coil?

Goodman says we need to charge this one with sub cooling and superheat.

Lets start with superheat:

1. Purge gauge lines. Connect service gauge manifold to base-valve service ports. Run system at least 10 minutes to allow pressure to stabilize. 2. Temporarily install a thermometer 4-6" from the compressor on the suction line. Ensure the thermometer makes adequate contact and is insulated for best possible readings. Use vapor temperature to determine superheat. 3. Refer to the superheat table provided for proper system superheat. Add charge to lower superheat or recover charge to raise superheat. 4. Disconnect manifold set, installation is complete. Superheat Formula = Suct. Line Temp. - Sat. Suct. Temp.

Here is the superheat chart. Give me the outdoor dry bulb and indoor wet bulb and that will tell us where we should be on superheat.Here is the chart

Hi, just checking in to see how things are going .Do you need further assistance?