Patent attributes
Example embodiments of the present disclosure relate to a heat pump assembly including a system or method for detecting a fault in the heat pump. Some embodiments include a method for detecting a switch over valve fault where the heat pump includes a refrigerant cycle, a compressor, a metering device, a first heat exchanger, an second heat exchanger, a temperature sensor, and a switch over valve, and where the method includes operating the HVAC system in one either a heating mode or a cooling mode, monitoring a refrigerant temperature associated with the refrigerant cycle using the temperature sensor, monitoring an outdoor ambient air temperature, determining a temperature difference between the refrigerant temperature and the outdoor ambient temperature, determining whether the temperature difference is greater than a predetermined temperature difference threshold, and declaring a switch over valve fault when the temperature difference is greater than the predetermined temperature difference threshold.