If the furnace overheats then a limit switch will open.
Furnace blower furnace fan limit switch wiring diagram.
Honeywell furnace temperature fan limit switch control the fan limit control turns the fan on and off in furnace applications.
Limit switch issue furnace blower fan wont turn off.
Wiring the furnace combination fan limit control using the honeywell l4064b as an example.
In some cases the limit switch will stick open and this will cause the fan to run continuously.
Assortment of furnace fan motor wiring diagram.
When the device is used both to control a furnace fan on and off as well as serve as a limit switch then all four terminals are.
It works off of temperature and also provides a high temperature safety limit this is a switch actually two switches which turns the furnace blower on and off based on the temperature of the heat exchanger.
Remove the wires attached to the old fan limit control.
Furnace fan motor wiring diagram wiring diagram for fasco blower motor valid blower motor wiring diagram lovely furnace blower motor wiring.
Mac 1175 wiring diagram mgh furnace wiring diagram models mg auxiliary limit control at bottom of heat exchanger green ground screw control panel cover 3 2 1 blower receptacle 3 2 1 fan off on 3 position switch black white.
This control can be wired to serve as a safety limit switch on a furnace by wiring just the limit terminals on the control.
That will cause the burners or heat source to shut off and the fan to run until the limit switch closes again.