In Japan, large amount of photovoltaic (PV) systems will be installed in the future power system due to rising environmental concern. The large installation of PV systems creates significant problems in the power system. One of the main problems is voltage rise at distribution line. Conventional voltage control devices such as SVR (step voltage regulator) based on line drop compensation method are not adequate to control the voltage because it is difficult to predict power output from intermittent distributed generators such as PV systems. Several methods have been proposed for voltage control [1], however recent researches focus on load control at the customer end for voltage control. Therefore, in this paper, local control of customer controllable load, heat pump water heater (HPWH), is proposed to mitigate voltage violation with independent operation of SVR.