Furnace Fan Limit Switch

Honeywell l4064a1347 fan limit control 8 insertion.

Furnace fan limit switch.

However for your own safety don t attempt to reset the switch without first consulting your furnace s instruction manual. It s possible to reset the switch at home when necessary by following a few simple steps. A limit switch also acts as a safety device for your furnace. Tell the fan when to shut off.

Fan limit switches are used on all types of building heating furnaces. The limit switch is a safety switch that monitors t. Definition of a fan limit switch. The fan limit switch on a heating furnace controls when the furnace blower fan turns on and off.

Universal 7 cam stat furnace fan limit switch 170 degree limit adjustable fan. If the temperature inside of the plenum gets too hot it shuts off the gas supply to your burners to prevent your. In this episode of repair and replace vance shows how to replace the high limit switch in a gas furnace. The furnace pilot is right under the fan limit switch and is fairly strong even at the lowest setting.

Temperature setting 1 this helps to avoid cold air drafts. 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. Tell the fan when to come on. Then blower runs on for 30 seconds and shuts off for a few minutes turns back on for 30 seconds and shuts off for a few minutes.

Honeywell furnace 8 combo fan limit switch l4064a1735. Essentially this means that it determines when the hot air should be blown through your ventilation system. Fan limit switch moves past fan off then past fan on blower doesn t start until about 10 20 degrees above fan on. A limit switch is a device that s located under your furnace s supply plenum.

A fan limit switch is a component of a furnace system that determines when the furnace blower assembly for hot air turns on and off. The function of your furnace limit switch is to tell the fan when to turn off and on depending on the temperature in the home. This control also provides a safety limit that turns off the burner or furnace if temperatures at the furnace are too high. The issue is that the fan limit switch is constantly heated to the temperature set which then turns on the fan.

It reads the temperature of the plenum and waits until it gets appropriately warm. Furnace fan limit switch. Burner turns on normally begins to heat. When the furnace is warm enough upon start up to begin heating the home about 20 degrees above room temperature it will tell the fan to come on.

A furnace s limit switch or fan limit switch has 3 main functions. What is a fan limit switch. It also determines if the furnace should be. After it is cooled down by the fan it will.

My furnace is about 30 years old. A furnace has two switches called a fan limit switch and a high limit switch these switches can be separate or in one package called a combination switch. Ending dec 16 at 5 51am pst 6d 18h.