The development of the era of using hot water for bathing is very rapidly used in hotels, homestays, and others. However, the use in hotels still uses a lot of LPG gas fuel that utilizes fossil fuels. So we need a Solar Water Heater (SWH), because SWH uses solar heat to heat water. On the other hand, the use of water has a shortage of high density so it requires a Phase Change Material (PCM) to reduce the high density of water. PCM in this study used a paraffin wax mixture and 10% copper powder. The purpose of this study was to determine the rate of decrease in water temperature, the rate of decrease in PCM temperature, the rate of release of water heat, and the PCM heat release rate. This study uses four variations of discharge, namely 1; 1.5; 2; and 2.5 LPM. Retrieval of data in this study by means of gradual discharging where every five minutes the tap water is opened then five minutes is closed. Data retrieval is carried out at a tank temperature of 70 ̊C and ends when the water bath temperature reaches 35 ̊C. The data taken during the discharging process is the water temperature in the tank, PCM in the tank and water in the reservoir. The result of this study is that variation 1 of LPM has the lowest temperature water drop rate of 8.88 ℃/hour and the lowest rate of decrease in temperature of PCM is in variation 1 LPM 8.92 ℃/hour. While the lowest water heat release rate is at 1 LPM, which is 444.8 J/s and the lowest PCM heat release rate is at 1 LPM, which is 33.19 J/s.