Hi, I was wondering if anyone has seen this problem. We have two WaterFurnace Envision units, each with a WF TPW32W02 thermostat. While we were out of town, it appears the thermostat on the second floor transitioned form cooling to heat mode. The best I can tell from energy use records, it happened right around midnight August 14. When we arrived at the house 18 hours later, the 2nd floor was over 100 degrees F and the heat was on stage 2. The temperature displayed on the thermostat was 11 degrees. One of the plug in clocks in the house was blinking, so it is possible that there was a power blip. The first floor system was operating normally in cooling mode. I turned the 2nd floor system off at the thermostat while we cooled things down with a whole house fan. The thermostat still would not display the proper temperature, so I unplugged it from its mount and disconnected the batteries, which were shot. When I reinstalled it, the temperature displayed correctly and I was able to turn on the AC and it operated normally. We have not had any need for heat or AC in the past month, so the system has been off. When I passed the thermostat, I noticed the temperature displayed was again incorrect, reading about 10 degrees cooler than actual room temperature. So my questions are: Has anyone heard of something like this happening before? Assuming that there is something wrong with this thermostat, what is the thermostat of choice for this system? Gary