An air handler control board is an essential component of any air conditioning system. It is responsible for controlling the operation of the air handler, which is the part of the system that circulates air throughout the building. The air handler control board is typically located inside the air handler and is responsible for controlling the fan speed, air temperature, and humidity levels. It also monitors the air filter, ensuring that it is clean and functioning properly. The air handler control board is connected to the thermostat, allowing it to receive signals from the thermostat and adjust the air handler accordingly. Without an air handler control board, the air handler would not be able to properly regulate the air temperature and humidity levels in the building. The air handler control board is an important part of any air conditioning system and should be regularly checked and maintained to ensure that it is functioning properly.