I have had a Nest Learning Thermostat for three years. It has run our multi stage furnace normally during that time, but we had some problems with the Nest not tracking our phone's locations properly, and going into ECO mode when we were still home. I decided to factory reset the thermostat and also reinstall both the Nest app and Google Home app. No changes were made to the thermostat wiring. After setting everything back up, Nest now tracks our phone correctly, but I notice two things that are different: 1) the Nest use to always turn the furnace on immediately when I manually set the temp. The moment I rotated the Nest dial to a higher temp, the furnace would kick on. Now, it takes a long lag time of ############ seconds for the furnace to turn on. It never did this before. 2) our furnace is now only running at a slow stage of heating. Normally when you first turned the furnace on in the morning it would run at the high stage, then go into the low stage once the house was heated. Now, it just runs in the low stage all the time. Is this because the thermostat is still " learning" about the system after I did the factory reset, or is something else wrong?
