Bunn coffeemakers brew coffee very quickly to retain the flavor of coffee grounds. The water reservoir on commercial models holds hot water at a brewing temperature so when pouring water in to make coffee the reservoir hot water makes the pot of coffee. This results in instant coffee brewing taking only a few minutes to completion. Household models do not have a water reservoir system to brew coffee instantly, but brew much quicker than other brands of coffeemakers. The warmer switch on a Bunn coffeemaker turns the metal plate under the pot on to keep the brewed coffee warm. This switch has a light in it to show the on position. When the light no longer illuminates, the switch is defective and coffee will not stay warm on the plate.
Unplug the Bunn coffeemaker and let it cool entirely.
Remove the coffee pot or pots from the warming plates and set them aside.
Carry the coffeemaker to a sink and tip it over to deposit water from the warming reservoir on a commercial model down the sink.
Wipe the exterior of the coffeemaker off with a dry towel.
Place a small flat screwdriver in the retaining ring of the switch. The retaining ring is a plastic cover that surrounds the hot plate "On/Off" switch on the front of the coffeemaker. Pry the retaining ring off the switch and set it aside.
Place a pair of needle nose pliers on each side of the switch with one hand. Hold the coffeemaker steady with the other hand. Pull the needle nose pliers straight out with medium force to unplug and remove the switch.
Place the new switch in position and press inward with needle nose pliers to attach it to the coffeemaker.
Place the retaining ring over the switch and press it in to snap into position.
Plug the coffeemaker in to an electrical receptacle and replace the pot.