Tips For Diagnosing Common HVAC Thermostat Issues

21 October 2015
 Categories: , Blog


The thermostat is more than just your interface with your HVAC system, it is the command center that ensures that your air conditioner and furnace are working properly. A malfunctioning thermostat can lead to an uncomfortable home, increased energy bills, or stress on your entire HVAC system. The following troubleshooting guide can help you diagnose the problem so you can get it fixed quickly.

Problem: The System Doesn't Turn On

Several things can cause a system failure at the thermostat. First, check your circuit breaker box for any blown fuses. If all looks well, turn your attention to the thermostat. Dirt and dust buildup around the thermostat can interfere with the temperature gauge. Vacuum it out with a hose attachment. You can also use compressed air, but make sure the system is turned off first so that it doesn't receive a false reading from the cold air. You may also want to use a clean paintbrush to dust between the small components inside the thermostat. If it still doesn't work, it may need replaced.

Problem: The System Won't Turn Off

On the other side of the problem, sometimes an HVAC system keeps running, even after it has cooled or warmed the home to the prescribed temperature. Your first task is to once again make sure it is clean and that no dust or dirt is affecting the temperature reading. Next, verify that no outside heat or cooling source is affecting the thermostat. For example, a television produces heat, which may fool the thermostat into thinking a room is warmer than it is. Make sure electronics and other heat sources are placed well away from the thermostat. If this isn't the problem, use a level to ensure the thermostat is perfectly level. Even being slightly askew affects the thermostat's reliability. If these fixes fail, your thermostat likely needs to be replaced.

Problem: Mismatched Temperatures

Do you need to bump the thermostat up to 80 degrees to warm the room to 70? This indicates a problem. Most inaccurate thermostats are caused by leveling issues, so use a bubble level or digital level to make sure the unit is installed correctly. Another issue can be poor placement. Thermostats should be installed on an interior wall, away from direct sunlight, electronics, and heat sources. Finally, the thermostat may need a professional calibration so it reads the temperature correctly. An HVAC specialist can perform the calibration, or replace the thermostat if it's an irreparable malfunction.

For more information, contact Reed Heating or a similar company.


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