How do you reset the fan limit on a furnace?
How to Reset a Furnace Limit Switch
- Locate your furnace’s heating duct.
- Locate the white limit switch.
- Look at each arm to identify the settings.
- Identify the component (setting) located in between the two arms.
- Set the temperature on the middle component to approximately 105 to 115 degrees Fahrenheit.
How much does a limit switch for a furnace cost?
You will need to buy a high limit switch that is produced by the same manufacturer as your furnace unit. Depending on who your OEM is, this component could roughly cost you anywhere from $4 to $25.
Where is the furnace fan limit switch located?
Your fan limit switch is located inside the furnace panel cover, usually near the upper right corner. The fan limit switch is responsible for turning the blower on and off at the appropriate times.
What are the causes when a limit switch opens?
Limit switch codes Limit switches turn off the burner and turn on the circulating fan if there is a high temperature condition in the furnace. When the temperature reduces to normal, the burner will come back on. The most common reason for limits to open is a plugged filter or a dirty blower wheel.
What would cause a fan switch to close?
The switch’s sensor becomes dirty and stops working correctly. The furnace filter is clogged and raises the temperature within the plenum prematurely, tripping the sensor. The blower motor stops working and overheats. These may cause the fan limit switch to stop working properly.
Why does my furnace high limit switch keep tripping?
A high limit switch will keep tripping due to a dirty flame sensor, short cycling, obstructed airflow, or a defective switch. These lead to overheating within the gas furnace that triggers tripping as a safety measure to prevent fires. Clean and replace dirty and worn-out parts to fix the problem.
Why does my limit switch keep tripping?
If the air inside your furnace gets too hot, the limit switch trips to prevent overheating. If the furnace high limit switch trips due to overheating, there is likely an airflow issue that is preventing proper air movement through the system. A dirty filter is the most common cause of airflow issues.
How much is a fan limit switch?
The furnace high limit switch helps to ensure your safety and the comfort of your home. Pretty handy for a part that costs as little as $4. It senses the furnace temperature in the plenum, and tells the blower fan to turn on and off as needed, according to pre-set temperature settings.
