A cooling unit includes a cabinet with a cooling chamber, a refrigeration system including an evaporator mounted, a compressor, a condenser, and a controller for controlling the cooling unit. The controller has a memory, a processor and an output interface. The controller monitors at least one parameter of the cooling unit, logs in the memory data corresponding to the at least one parameter, and outputs the logged data via the output interface. The cooling unit can include a sensor that monitors a parameter that is logged in memory. The sensor can be a temperature sensor. The logged data can be compared to stored error conditions to detect whether an error condition has occurred. If an error condition has occurred, an error code is logged in memory and can be outputted via the output interface.