So you have 2600 sq ft in Ca where its not that cold and you think you
need 200k btu or so, Im no pro but you need a written load calculation
done on the house to know what you need in Btu. Did anyone do one? So
you might have been oversized and may still be. Im in zone 5 to -20f
1800sqft on a windy lake and was calculated to need 50k btu on a super
insulated house. I actualy only need my 47000btu 1st stage, never the
78000 second stage. One thing you need new windows and probably
insulation, I would ask for a copy of the written load calc all these
pros did [sure] and go with the smallest unit you can. And look into new
glass, and figure that into your unit size if you can afford it. You
are loosing winter and summer without Low E argon glass, with the heat
up you describe you likely have regular glass.