Furnace Blower Fan Limit Switch Wiring

Turns fan on and off according to plenum temperature via helical bimetal sensing element.

Furnace blower fan limit switch wiring. If you have one thats your. Certified OEM Harman Heatilator Furnace fan limit control sensor limit switch. Video demonstrating the standard wiring for the primary blower motor found in most furnaces and air handlers in residential HVAC.

Wiring the Furnace Combination Fan Limit Control using the Honeywell L4064B as an Example. A control wiring problem where the insulation on the wiring is worn off. 38 out of 5 stars 3.

A bad relay fan sequencer relay fan limit control or circuit board with contacts sticking this depends on the type and age of the furnace A problem with the limit switch or a problem that is causing the limit switch to open. It is in parallel with the safety and gas valve circuit. 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.

From the factory this setting out of the box is 200 F. Turn on electrical power to the heating system. Is the least efficient diagram among the electrical wiring diagram.

Includes manual and automatic fan onoff settings. Controls high limit and fan motors in forced air heating systems. If the Fan Limit switch worked normally continue as follows.

The blower fan draws cool air from the occupied space through return ducts pushing that air up through the furnace heat exchanger where it is heated and onwards through supply ducts. Pellet and Coal Furnaces - PF100 PF120. How it Works Honeywell Furnace Temperature Fan Limit Switch Control When the furnace heat exchanger heats up the bimetal twists causing the round dial shown in the picture to turn.