Furnace control boards, often called controllers, are used to coordinate the operation of a furnace and read and react to various sensors. Their digital design enables furnaces to operate more safely and efficiently than purely mechanical furnaces.
One advantage of control boards is their ability to detect problems within the system. In older systems, a thermostat failure could cause the system to run constantly or stop running at all. Control boards can detect errant thermostat readings and indicate the nature of the problem. Fault codes displayed on control boards can allow homeowners to avoid having to inspect the entire system when it's not functioning properly. When linked to appropriate sensors, control boards can also halt the system if it's not operating within safe parameters.