The use of split-type air conditioners is popular in residential and commercial buildings of everywhere in the world, and the demand increases each year continuously. In this regard, theoretical and practical case studies of fault detection and diagnosis of this air conditioner constitute a vital part of technical service of corresponding corporations. Moreover, quick and convenient fault detection and diagnosis are substantially important for effective implementation and decision on servicing and repairing air conditioning. In this study, a fault-test apparatus of split-type air conditioner has been designed to supply quick and convenient fault detection and diagnosis. In order to conduct performance analysis, 16 different faults have been formed on the control unit of this apparatus, and the on-off switches have been used to create the faults. The tests have been performed according to the standard cooling capacity. The behaviour of the system has also been investigated under the normal and faulty conditions. Results from diagnosing the faults have been presented and discussed, and they have also been compared with the normal condition. In addition, solutions offered against the faults have been also provided to operators.