Furnace High Limit Switch

When the temperature gets to be too high the high limit switch stops. A high-temperature limit switch also called a fan limit switch or simply a limit switch is an important device used in forced-air furnaces powered by gas or heating oil.

Honeywell Furnace Temperature Fan Limit Switch Control Heating

Simply put it senses the temperature of the furnace and tells the blower fan to turn on and off at the appropriate times.

Furnace high limit switch. A limit switch is a device thats located under your furnaces supply plenum. What Is a Furnace Limit Switch. The limit switch is a safety switch that monitors t.

A high-limit switch is a protective part of a furnace designed to keep the mechanism from overheating itself. If the high limit switch was bad the furnace should not fire. What is a High Limit Switch.

Furnace High Limit Switch vs. It reads the temperature of the plenum and waits until it gets appropriately warm. This component is connected to the blower motor as well as the gas valve and consists of a probe that detects temperatures mounted to a metal plate.

If the temperature gets too high the furnace could be overheating so the high limit switch will shut off the gas valve stopping the heating. Limit switches turn off the burner and turn on the circulating fan if there is a high temperature condition in the furnace. The high limit switch is also there to act as an intermediary with the gas valve.

When the high limit switch trips the flameheating element will be shut off and the blower will continue to run to clear the heat. Once the plenum reaches a specific temperature the limit switch sends a signal to the air handler to begin running and delivering warm air to your home. Should overheating the trip the high limit switch several times the furnace will switch to a lockout mode.

The limit switch can be tested before replacing. But if that supply of air becomes too hot the job of the high limit switch is to shut off the gas valve to stop the heating. Ad Search Faster Better Smarter Here.

The limit switch is a safety switch that monitors the air passing over the heat exchanger and will shut the furnace off if the system overheats. When the furnace runs as we touched on above the primary role is to switch on the blower when the air is hot enough. The high limit switch is a furnace component that controls elements of operation and safeguards the system.

Essentially it senses the temperature of the furnace and tells the blower fan to turn on or off at the appropriate times so that it can properly circulate air to your home. A high-temperature limit switchalso known as a fan limit switch or a limit switchis an important piece in a furnace. This control also provides a safety limit that turns off the burner or furnace if temperatures at the furnace are too high.

If the high limit switch fails then the furnace might cycle on and off and will not function properly. As the furnace starts running the high limit switch will switch on the blower fan when the supply air becomes hot. The limit switch shuts off the burner when the temperature exceeds a preset temperature.

This is the role it plays in every cycle of your furnaces normal operation. There is a difference between a limit switch and a rollout switch. In this episode of Repair and Replace Vance shows how to replace the high limit switch in a gas furnace.

Ad Search Faster Better Smarter Here. The blower will continue to run until either the system is reset or the limit switch closes. Ad Improve Your Business ROI - Get A Better Deal On Furnace.

Turning the fan motor on and off is the high limit switchs main job. The limit switch has two functions. FanLimit switches are used on all types of building heating furnaces.

Equally important a furnace pressure switch located inside a furnace motor compartment is designed to detect negative pressure inside the unit and when detected shut the furnace down. When the temperature reduces to normal the burner will come back on. The fan limit switch on a heating furnace controls when the furnace blower fan turns on and off.

I believe high limit switches are normally closed and they should always fail open. Furnace Pressure Switch Furnace limit switches may be mistaken for furnace pressure switches but the two are not interchangeable. This switch plays a role in the normal operation of your furnace.

The high limit switch in your gas furnace is a small part with two very important jobs. A furnace is at a risk of overheating any time airflow is limited from passing through the heat exchanger. Ad Improve Your Business ROI - Get A Better Deal On Furnace.

American Standard Trane High Limit Switch Swt01280