The thermostat is pretty much the brain of an air conditioning system. The thermostat tell the rest of the air conditioning and heating system when to come on and when to go off. There are many different brands of and styles of air conditioning and heating thermostats.
One of the secrets behind keeping your utility bill as low as possible is leaving your air conditioning and heating thermostat alone. Just like the man says about the "Showtime Rotisserie", "set it and forget it". Constantly adjusting your thermostat not only costs you money on your utility bill, it causes you air conditioning and heating system to work harder trying to keep up with your everchanging comfort level. Unfortunately, the most common problem with an air conditioning and heating thermostat, is the operator.
Air conditioning and heating thermostats can experience several different malfunctions: *Many heating and cooling thermostats are improperly calibrated--meaning, they don't sense the surrounding air temperature properly, thus it doesn't cycle the air conditioning and heating system on and off correctly. Improper calibration on an air conditioning and heating thermostat can cost you money on your electric bill, as well as increase discomfort levels and overall disatisfaction with your air conditioning and heating system. Ideally, a properly calibrated heating and cooling thermostat should be within 1 degree of the actual room temperature, however, calibration within 2 degrees is normally accepted. Many air conditioning and heating thermostats are out of calibration by at least 5-8 degrees.
You can easily check the calibration on your air conditioning and heating thermostat by using the following method:
Obtain a small thermometer that you can easily place near(on top of preferrably) your air conditioning and heating thermostat. Leave in place at least 10-20 minutes in order to get a more accurate reading of the room air surrounding the air conditioning thermostat. Once you get a reading you feel is accurate, compare it to the temperature reading on your actual air conditioning and heating thermostat.
The difference between the two is how "far out of calibration" your air conditioning and heating thermostat is. If the temperature difference is more than 2 degrees, you should have a professional air conditioning repairman evaluate and recalibrate your air conditioning and heating thermostat. *Other malfunctions with air conditioning and heating thermostats range from not working at all, to bringing the heat and air conditioning on at the same time. It's not recommended for a homeowner to attempt to change their own thermostat for several different reasons--primarily, they could cause bodily injury, as well as a host of other problems that can be caused by improperly installing, wiring, and operating a air conditioning and heating thermostat.