Coffee Maker: Heats for too Long or Won't Shut off

If your coffee maker heats for too long instead of shutting off, the issue could be with a switch, also known as the control board, input board, or micro switch. Depending on the model of coffee maker you own, there can be a variety of these switches. This is more of a problem with a circuit board than just an exterior switch. The circuit board signals the heating components to begin heating when you flip an exterior switch to begin brewing. To access the circuit board for repair, first make sure the unit is unplugged. Remove the carafe and flip the unit over to access the bottom. Remove the plastic bottom cover by undoing the screws that hold it in place. The circuit board should be visible, and may be held in place with one or more screws. Removing the motherboard and replacing it with a new one may require a soldering iron to detach the wires from the board.

A faulty thermostat in your coffee maker can get stuck in the on position. If this happens, the thermal fuse acts as a failsafe and will stop electricity from going into the heating element if it gets too hot. To repair your thermostat, remove the carafe from your coffee maker and flip it over. Remove the screws holding the bottom cover in place. The thermostat is a small white part, made of plastic. You can use a multimeter to test its continuity before deciding to replace it. Pry off the metal clip that holds the thermostat in place with a screwdriver. If the wires to the thermostat terminals are welded in place, you may need to install your new thermostat with terminal ends, also known as spade connectors, so that you can cut the wires to the terminal and reinstall them. Cut the wires and strip the ends. Place the terminal end on the wire and crimp it into place. Reinstall the thermostat into place using the metal clip, and compound glue if necessary.