A furnace actuator is a device that is used to control the operation of a furnace. It is typically connected to a thermostat and can be used to regulate the temperature of a room or home. The actuator works by receiving signals from the thermostat and then activating the furnace accordingly. This can be done either manually or automatically, depending on the type of actuator being used. The most common type of actuator is the mechanical actuator, which is connected to a series of gears and levers that control the operation of the furnace. This type of actuator is usually the most reliable and efficient. Other types of actuators include electronic, pneumatic, and hydraulic actuators. Each type of actuator has its own advantages and disadvantages, so it is important to choose the right one for your specific needs.