Refrigeration 101

[Gary]

I'm a legend in my own mind... lol

[Heeellp]

That maybe true, but I am impressed. Gary, I have several quick questions if I may (homeowner). I know this is installation specific so I will try to keep it concise and compact. It deals with a problematic installation (as most do) and a dealer who can't seem to get it right. Can you try to steer me right? Thanks.

3 ton heat pump (two speed ultra tech scroll compressor) split system. 95 % AFUE variable speed furnace matched coil System has had MANY problems since installation. TXV and heat pump replaced due to non-condensibles. Manual states: subcool 5-7 (no plus or minus for two speed pumps) and superheat values of 7-9 (no plus minus). After two years of somewhat adequate cooling I noticed it started running longer than usual cycles. Tech reluctantly came out again. Checked subcool (10-11) and superheat of 20. He added refrigerant until subcool was 9-10 and superheat was 10. He stopped. Please understand, I am a layman so go easy. Unfortunately I do no have the delta T for you. Ambient was around 80-82 degrees and compressor was on low speed. System runs way too long for these values (based on previous years of usage). It simply does not cool the house like it once did (added 44 bags of cellulose insulation in attic). Any ideas? Please?

Found the issues as suspected. Techs would not adjust TXV. Field rep did. System runs much better. Thanks.......