Electric Cooktop Element High Heat

When you’ve got a cooktop element that is always on high heat regardless of where the infinite switch is set to (Low or Medium, for instance), then you’re dealing with a failed infinite switch.

Infinite Switch

The infinite switch works to supply L1 and L2 to the element. When the user selects a lower temperature, internal mechanisms work to cycle the element on and off. Much like a duty cycle. The surface elements generally do not regulate the heat output the way a gas burner does where you can reduce it. So it cycles on and off.

When you have the unit where it’s always HOT, then you’ve likely got a failed infinite switch.

In this diagram, notice how the L2 leg of voltage goes through a few rectangles? That indicates a bi-metal heater. When current goes through that heater, it heats up and opens and closes the bi-metal, opening and closing L2 to the heater. When you select a hotter temperature on the knob, the ramp in the infinite switch puts more pressure on the bi-metal strip, so it won’t open as easy.