@andybrwn@ai6yr Thanks so much for the info. Ick. A/C guy coming Tues. I already did the multimeter tests.. If it was my house I woulda popped on a new thermostat or bypassed the thermostat for downstairs if it got really bad…. Alas it’s a rental until our home is rebuilt (fire). Currently only 75 downstairs. So I can’t complain.