A properly functioning heating system requires many separate components to be working properly both on their own and in concert with each other. Although it often isn't seen as critical, a thermostat in good working order is vital for your furnace to function as it should. Thermostats also tend to be one of the cheapest and easiest parts of the system to fix, which makes them a good candidate for early troubleshooting if you are experiencing problems keeping your home cool. This guide will help you to understand the role your thermostat plays in heating your home, which symptoms likely indicate a problem, and how you can test the thermostat to be sure.

How Your Thermostat Works

While the role of your thermostat may seem obvious, it is a much simpler device than most people understand. In most cases, the thermostat is effectively an on/off switch for your furnace. When the temperature is cooler than the desired temperature set on the thermostat, the furnace turns on. Surprisingly, the thermostat does not control the actual temperature of the air that is traveling through your vents. Instead, it simply runs the furnace for as long as it takes to reach the desired temperature.

Understanding how your thermostat works can help you to understand if it is functioning properly. Most people expect that turning the temperature higher should cause warmer air to be blown into rooms of the house, but the temperature of the air coming from the vents will generally always be the same. Cool air coming from your vents while the furnace should be running can indicate a problem, but it is not a cause for concern if turning the thermostat higher does not result in warmer air.

Signs of a Failing Thermostat

Unfortunately, many of the symptoms of a failing thermostat can also indicate other problems with your home's heating system. Since the thermostat is usually the cheapest possible cause, however, it is a good place to start. Any of the following may indicate that your thermostat is failing or has already failed:

  • The thermostat itself seems to have no power, refuses to turn on, or seems unresponsive
  • Your vents are blowing warm air, but the furnace seems to be cycling on and off more than it should be
  • The furnace refuses to turn on
  • The furnace continues to run even after the target temperature has been reached

Remember that the thermostat only controls when the heat is turned on and off, so problems with a lack of airflow or air that is too warm or too cold are unrelated. Instead, consider the thermostat a potential culprit any time you are having an issue with the system turning on or remaining off when it shouldn't.

Diagnosing Your Thermostat

If you think your thermostat may be the cause of your heating troubles, then there are a few simple steps you can take to test it. Before proceeding, turn off the breaker for your furnace or otherwise disconnect power from it. You will then need to remove the thermostat from the wall. In most cases, you should be able to simply pry it off. If it will not come off easily, check for mounting screws.

Thermostats switch the furnace on and off using a pair of red and white wires (if you have additional wires, they are likely for your air conditioner) which should be attached to the back of the thermostat itself. Simply shorting these two wires together should force the furnace's burners to turn on. Believe it or not, there isn't much more to the basic operation of a thermostat. If you connect these two wires (it's fine to simply wrap them together) and turn the breaker back on, your furnace should run. If it does, then your thermostat is likely the problem and a replacement should be in your future. If the furnace does not turn on, it's time to begin looking for problems elsewhere.For more information, reach out to furnace repair services near you.