Electronic flushing and pressure testing unit with oil-free compressor. Only one device for flushing with water or a water/air mixture, disinfection, cleaning, preservation of pipe systems, for pressure testing of pipe systems and vessels with compressed air or water, e.g. drinking water installations, radiators or area heating systems, for pressure testing of gas installations with compressed air, as a pneumatic pump for controlled filling of all types of vessels with compressed air, e.g. for pumping up expansion vessels or tyres and for operating pneumatic tools.