Resetting your furnace limit switch is a simple procedure that can resolve frequent furnace problems.
Find your furnace’s heating duct.Â
To open the panel, you’ll need a screwdriver.Â
The white limit switch is located at the top of the panel and can be covered by a silver or white cover.Â
To access the switch, remove the lid.
After making the necessary changes, use the screwdriver to close and secure the panel.
Firstly, turn off the furnace’s switch or circuit breaker. After about 10 seconds, turn the power back on and see if the furnace regains power. For older furnaces, the procedure includes:
Note: To avoid any electrical dangers, make sure the furnace’s power source is entirely turned off before attempting a reset.
A furnace limit switch is a component of a forced-air furnace that activates the furnace blower after the desired heat level has been achieved inside. It is important because the limit switch monitors the temperature and turns off the burners if the furnace begins to overheat. Without a working furnace limit switch, a furnace cannot regulate the temperature in conjunction with a thermostat.
Common signs of a bad limit switch are repeated boiler shutdowns, continual blower activity, and inconsistent heating. Other symptoms include:
Homeowners can do simple diagnostics such as checking damage and ensuring the furnace is properly installed.
One of the most typical issues with a faulty high-limit switch is that it fails to notify the blower fan to turn off. If your fan continues to run (and you’ve checked that your thermostat is set to AUTO rather than ON), it could be a symptom of a faulty high-limit switch. Other common indicators that help you identify faulty furnace high-limit switches include the blower running constantly, repeated shutdowns, and fault messages on the thermostat.
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Get Free EstimateA bad limit switch on a furnace can cause many performance issues, including continuous blower fan operation, short cycling, overheating, and inconsistent heating. It can also result in no heat generation or burner shutdowns due to inaccurate temperature measurements.Â
Follow these Steps to Reset the Gas Furnace Limit Switch
To reset the limit switch on a furnace vent system, turn off the power at the breaker. Next, locate the limit switch on the blower housing and push the reset button if present. Always make sure it is clean and debris-free. Finally, restore electricity to the furnace and test the system.
One of the most typical causes of a high-limit switch staying open is simply due to dust and dirt. Other reasons also include malfunctioning of the blower motor or blocked vents. Â
You can fix this issue by cleaning and replacing it. Make sure all the vents are unblocked and properly cleaned. Check the blower motor because a faulty motor can create such issues. If the issue persists which means there is some fault in the high-limit switch itself, so replace it.
If the air within your furnace becomes too hot, the limit switch will trip to prevent overheating. If the furnace’s high-limit switch trips due to overheating, there is most likely an airflow issue. This limits proper air movement through the system. Check your air filter and replace it if it’s unclean.
After resetting the limit switch on your furnace, ensuring the pilot light is properly lit can prevent further shutdowns and maintain efficient heating. Check out how to Light a Furnace Pilot
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Get Free EstimateBypassing a furnace limit switch is a high-risk action that should only be used in extremely short-term (temporarily)and in controlled testing scenarios.
Bypassing a furnace limit switch is a high-risk activity. The limit switch is meant to turn off the furnace if the temperature reaches a dangerous level, which prevents overheating or fire threats.
Bypassing the fan limit switch in a furnace can cause risks. A furnace gets overheated to the point when components, such as the heat exchanger could fail and emit carbon monoxide into your home. There is an increased fire risk because of excessive heat with no way to turn off the furnace. Moreover, internal components, such as coils and ducting can melt which results in costly repairs or the need to replace the entire system.
Proper maintenance involves regular inspection and replacement of air filters. It also includes the cleaning of the clogged or dirty filters and inspection of the blower motor so it does not cause overheating. In case of severe issues, getting professional maintenance services from All Season Home HVAC is ideal.
Airflow restrictions that are caused by a dirty filter or system obstructions are common causes of limit switch failure. Maintaining proper airflow impacts positively to prevent overheating and damage to the limit switch.
Regular filter replacement, cleaning of the air ducts, and cleaning of the blower motor are necessary. Because blockage can cause overheating that activates the limit switch that shuts down the boiler for safety.
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Get Free EstimateIf your furnace doesn’t turn on or off properly, has uneven temperature control, or overheats, it is a sign that your limit switch is bad.
In most cases, the limit switch is located inside your furnace’s cover panel. (Depending on your system model, you need to remove this panel with a screwdriver.) On older furnaces, it is located on the outside of the furnace.
an open limit switch on a furnace can be caused if the air within your furnace becomes too hot. This causes the limit switch to trip to prevent overheating. Other reasons are reduced airflow, electrical issues, and thermostat issues.
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