Your furnace system comes with a variety of safety devices that help increase personal safety. Your furnace door switch, though small, is one of them.
It is the first thing that must be switched/ pressed on when the front panel is removed, the switch kills the power of the furnace so you or the technician can go on and start troubleshooting the furnace.
When the panel is in place, the switch remains turned off and the furnace works as it should be. A common problem is homeowners tape down the switch for some unthinkable reason. This is a bad idea, the switch is a safety measure and must be left freely and functional.
Work and live safely, get a furnace door switch replacement today if yours is already mechanically defeated. We have a long list of durable door switches for you to choose from.