Had OnStar installing a Nest Learning thermostat for my heat pump/furnace in early November. I’ve noticed on cold days (morning temp <40F) that sometime mid-morning, the system just blows cold air, dropping the temperature in the house. I can turn on the emergency heat which will warm it up. I’ve gone and flipped the breaker for the furnace and it seems to fix it as well. On the thermostat, I never see Stage 2 heating or auxiliary heat at all. Had OnStar come back and look at it and they say it’s an HVAC issue, but this never happened prior to having the Nest. Wondering if the W1 wire should go to W2 instead?
Old setup:
New Setup:
