5 Possible Reasons Why Your Furnace Will Not Turn On With Thermostat

While you anticipate your heating device to work efficiently every time you switch your thermostat on, in some instances it does not happen due to several defects that can make your furnace refuse to turn on.

Sometimes, switching off the furnace for several hours can help you reset the system and fix the issue. However, if the problem persists, you can fix this issue yourself if you know some DIY troubleshooting tips. However, if they do not work, contact our heating contractor in Gainesville to resolve the issue.

Five Possible Reasons Your Furnace Is Not Turning On With The Thermostat

Below are some common reasons your furnace system is not functioning:

  • Thermostat Issues: The thermostat controls the furnace operation. Nevertheless, if your thermostat is not working correctly, it cannot allow your furnace to understand when to switch the heat ON. Hence, the first thing you must do is examine your thermostat settings.
    Ensure the thermostat is turned to heat mode. You can remove the thermostat’s cover to examine any dirt build-up, which could impact the thermostat’s detectors. You can also wipe the thermostat with a soft scrub to eradicate any dust you see.
  • Improper Maintenance: Heating maintenance is usually neglected or not considered by many homeowners. Many issues can arise if your heater isn’t regularly inspected by a skilled expert or is improperly maintained. If you notice an odd noise or smell at your place, it could be a concern with your heating device. When this happens, it is better to consult our heating repair expert in Gainesville to fix the fault.
  • Dirty Air Filter: Another reason for the furnace not turning on could be the clogged air filter, as the furnace air filter should be replaced every three to four months. If the air filter is clogged, it can restrict airflow, indicating that the machine has to perform hard to warm your house, and it’ll take an extended time to reach the expected temperature.
  • Clogged Ducts Or Vents: Another significant and recurring reason for the furnace not working is a vent or ventilation system obstruction. Therefore, regularly cleaning your vents is important for enhancing air quality, the system’s performance, and efficiency.
    It also ensures the furnace runs smoothly, postponing the need for replacement and heating repair in Gainesville. Inspect the air vents and other outlets that carry air in and out of your home. Dust and debris could accumulate in these regions, which need to be removed.
  • Faulty Flame Sensor: When the ignition starts in a furnace, the detector notices that the gas is burned and there is a flame. If there is no visible flame, the flame sensor closes the gas valves, guaranteeing that natural gas doesn’t get into your house in its raw form. Nevertheless, if your furnace has a faulty flame sensor, it will not detect the flame even when there is a flame and does not let the fuel into the combustion chamber.


At Affordable Heat & Air, we provide heating repair service in Gainesville and the surrounding areas. We have the right resources and crew of qualified technicians to help you with your furnace repair and replacement services. To know more, call us at (940) 580-2905.