I have a 20-year old programmable thermostat in my house, actually I have two. I installed them myself a few months after moving in to replace the poor quality builder's grade thermostats, and to have the ability to program the settings. They are Honeywell CT3300s, which if I recall I bought for about $45 or $50 each. They have a typical program, 4 time\/temp settings for M-F, and 2 settings for weekends. Once they were installed, they were easy to program and have worked well. They occasionally need new batteries, 2 AA size.\n\nYesterday, we were out for most of the afternoon and evening. I had set the thermostats to 62° F, my away temperature, when we left. When I got home, the downstairs thermostat read 17° C :eek:! I knew that was about right, but I was puzzled at what made it change from F to C.\n\nThis morning, I found the old manual, and read how you can change the readout between F or C, by turning a screw on the back plate of the thermostat by one turn. I dreaded removing this thermostat because I vaguely remember having trouble installing it. (The thermostat wire was too short. I struggled with it for a while, and finally spliced on about 6-8" lengths for each of those wires. It was a pain.)\n\nWhen I got a bunch of screw drivers and a flashlight, I saw that the thermostat now read in °F again. OK, so I never had to pull it off the wall (a good thing), but I'm wondering if I've gotten a warning of future failure.\n\nSo I quickly looked at what's available on Amazon. Aye caramba! There are self-programming thermostats that are controlled by smart phones, selling for $250 to $300!! I really don't want that. Isn't there a roughly equivalent replacement for a reasonable price?\n\nMy system is standard for the mid Atlantic region: natural gas-fired forced-air heat and electric air conditioning all driven by a common air handler. No heat pump or electric heat. If I recall, the thermostat control wire has 4 conductors.\n\nI know Imcloud works in home heating and cooling. Any others with recent thermostat experience?