A limit thermostat is a safety device designed to open or break the circuit in high temperature or high current situations. They are rated for both current and temperature.

The liquid level control board is an electronic device designed to automatically fill the brew tank with water when it senses a low level condition. It works in conjunction with the Liquid Level Probe and tank ground. A low AC signal is applied to the probe from this board. Minerals in the water complete the path from the probe to ground. When no ground is present and the machine is “on”, the liquid level board will then send a signal to the refill solenoid to energize. It will de-energize when the probe again senses water.

The liquid level probe is a sensor that monitors the water level in the tank. When water comes in contact with the probe it completes the circuit to ground. Once the circuit is complete the control board knows the take is full and opens the refill circuit shutting off the incoming water supply.

A control thermostat is a device designed to keep water at a constant temperature. It is preset for a specific temperature and will open and close its contacts to maintain that temperature.

A microprocessor carries out a number of electronic functions in an integrated circuit. The microprocessors found in BUNN equipment are used to control water temperature, water delivery, motors, and other integrated components needed for machine operation.

The multimeter is a handheld instrument designed to measure current, resistance, and capacitance. As one of the most valuable tools a technician uses on the job, it is important that it is used correctly. Before using a multimeter you should read the safety information and become familiar with the safety warnings and cautions. Taking the time to review the safety information is for your own safety as well as protecting the meter and all the equipment involved.