Your furnace abruptly stopped working and you can't get it to turn back on, so you call the furnace repair company. The repairman tinkers around for a while and informs you your roll out switch went off, and he needs to inspect your furnace and duct work for any problems. Roll out switches are one of your furnace's safety mechanisms to prevent overheating.
The roll out switch is a safety mechanism on your furnace. If the furnace overheats, the roll out switch shuts the furnace down to prevent a fire from starting in your furnace. This safety feature not only protects your home from fire, but also prevents damage to your furnace.
How it Works
When your furnace reaches a temperature of more than 350 degrees, the roll out switch shuts off. The switch is wired to the circuits of your furnace's internal power source. When the switch turns off, power is cut off to the furnace, and the furnace immediately shuts down.
Location and Identification
Roll out switches are generally located near your furnace's burner box. They are round, with a switch sticking out of the top. Two strips of metal of equal length (about an inch long each) are attached to either side of the switch. The metal strips have a hole at the end furthest from the switch.
More About Roll Out Switches
If your roll out switch goes off, you can reset it yourself by pressing the center button. However, you still need to call out a furnace technician to have the furnace looked at. The roll out switch tripped because of a problem with your furnace, or because the switch itself is faulty. Ignoring any furnace problem is potentially hazardous.