When most people think about an expensive HVAC failure, they picture a compressor, a rooftop unit, or an entire system needing replacement. Those repairs can be costly, but they are not always the failures that have the greatest impact on the business. Many times the most disruptive HVAC failure begins with something small: a control board, variable frequency drive, motor, sensor, actuator, contactor, or another critical component. Not too expensive, but costly if you have t