A furnace controller is a device that is used to regulate the temperature of a furnace. It is designed to monitor the temperature of the furnace and make adjustments as needed to maintain a desired temperature. The controller is typically connected to a thermostat, which is used to set the desired temperature. The controller then uses a variety of sensors to measure the temperature of the furnace and adjust the furnace’s settings accordingly. The controller also monitors the fuel consumption of the furnace and can adjust the fuel flow to ensure the furnace is operating efficiently. In addition, the controller can be programmed to turn the furnace on and off at certain times of the day, allowing for more efficient energy use. The furnace controller is an important part of any furnace system, as it ensures the furnace is operating safely and efficiently.