We are in GA, in a brick house which retains heat...I noticed it seemed warm at dinner time, but I had the oven on. So now I am at the computer, and still warm. Go to see what the thermostat says, and it's a bunch of letters meaning nothing to me. Call DH who says the batteries must need to be replaced. I didn't even know it ran on batteries...thought it was wired somehow. So he put new batteries in it, and is now looking for the instructions on how to reprogram it....chuckle, chuckle. Maybe now he'll replace the batteries once a year, along with the smoke detector! Not something he wanted to do on Saturday night!