Is Your Furnace Fan Running Continuously? Here's What You Should Do

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A furnace's fan sucks air into the furnace. It also pushes heated air through the duct system and into a home. A furnace that runs non-stop usually leads to needless energy consumption. And if it runs when the furnace is off, it will end up blowing chilly air into your home, something that will cause a lot of discomfort. The following are furnace tips that will help you fix this problem.

Change the fan settings of the room thermostat

To help conserve energy, furnaces are designed to only work toward a set temperature. And when the set temperature is achieved, the furnace is supposed to stop functioning. The room thermostat usually helps to control this process.

To make furnaces more versatile, manufacturers usually give homeowners a degree of control over this process. This includes the option to choose whether to "untie" the furnace fan from this on-off process. As a result, one can simply make the fan run independently by changing the fan-control setting at the room thermostat from AUTO to ON. This will make the fan run even when there is no need for heating and may therefore be the source of always-on furnace fan problems.

Simply changing the settings back to AUTO mode will make the running of the fan dependent on whether you home needs heating or not. It will ensure that the fan runs only when the furnace is heating your home.

Replace the fan limit switch

To prevent a scenario in which the furnace fan blows unheated air into your home, manufacturers usually fit furnaces with a fan limit switch. This switch works by monitoring the temperature in the supply plenum and for as long as the temperature hasn't risen high enough to warrant the heated air getting blown into a home, the switch will keep the furnace fan off. However, when the temperature is high enough to warm the home, the switch activates the furnace fan, allowing it to blow air through the duct system and into the home.

The fan limit switch usually monitors the supply plenum temperature by using a thermostat. If this thermostat malfunctions, the fan limit switch won't be able to accurately detect temperature changes. This will then limit the ability of the fan limit switch to keep the furnace fan from running. This can then lead to a condition where the fan runs continuously, something that will then negatively affect the efficiency of the furnace. Replacing the fan limit switch will be enough to solve this problem.

Talk to a company like Action Appliance Services for more information.