In the summer time, when I turn on my air conditioning and set my desired temperature on the thermostat (usually 23 degrees Celsius0, the temperature is quite accurate in all areas of the house. In the colder months, however, when I turn on the heat, it's always way off. For example, I set it for 22 degrees Celsius today, and when I went around with an electronic thermometer, the actual temperature was only 21 degrees downstairs and around 20 degrees upstairs. I had the furnace examined last year and everything came back fine. This is very annoying because it feels like I'm wasting money on something that isn't being delivered. Has anybody had similar issues?