Disclosed is a monitoring and control system for an air source heat pump apparatus having a controller to control at least one operation of the heat pump apparatus, a temperature sensor to detect the temperature in a specified area at, near, and/or around the controller, and an operable component, the system including a control program to: determine the temperature based on the detected temperature of the temperature sensor; determine whether a first condition exists, the first condition including a determination that the controller is powered, but the operable component is not operating; determine whether a second condition exists, the second condition including a determination that the controller is powered, and the operable component is operating; and based at least partially on determinations (a)-(c), determine the ambient temperature at or around the heat pump apparatus.