facts:
Location: Southern Middle TN
Out Side Temp 84
TemoStat setting 77
Room Temp. 60" off floor @ termostat 77
Return Temp 24" off floor 69
supply Temp closest vent 53
Ceiling Temp 78

Turned unit off room temp 1 hour later 77

Problem: termo set at 77, unit will never shut off even though room temp reads 77, units continues to run but temp never drops lower then 77. I thought it might be to much heat transfer from attic. but ceiling temp disproves this. Duct work is in the crawl space. I had the unit services about 3 weeks ago. Tech cleaned the unit said it was in good shape, needed just a touch of freon. Thanks Hammy