Hi, I had my local Geo service company (very competent) work on my system recently and we decided to replace my old Honeywell T8411R stat (17 years old, original with geo install) with a new TH8321 VisionPRO series. Now I am having some "non-traditional" heat cycle behavior. My old stat in frigid weather (maybe temp in the teens or lower) would run the compressor constantly and cycle aux as needed based on the T8411's droop algorithm. The new stat is almost acting like it has little intelligence and running a fixed heat cycle algorithm. When the system compressor/fan comes on, it kicks in Aux about 1 minute later, runs aux for about 3 minutes until de-energized, then compressor continues to run another minute until full system off. Time between heating cycles is around 7-8 minutes on average. Not what I am used to and doesn't seem very efficient to me. I have this information into my HVAC guys and am awaiting feedback but wanted to see if anyone here has an opinion. Following are some measurements I made Friday evening and Saturday morning as reference.