PURPOSE: To enable a use of the capacity of the titled hot water heater in response to the actual requirement at the user side by a method wherein a required energization time to be applied to the heater is calculated in response to the actual use of hot water volume at the user side and the expected volume of use for tomorrow to be fed from the input device.
CONSTITUTION: In an energization time calculation device 13, a constant C added with a rate of margin is multiplied by HGmax to calculate an energization time Hs. In a boiling point setting device 14, a water feeding temperature Ti in the hot water storage tank 1 is measured by a temperature sensor 9, and a boiling point To is set in reference to an energization time Hs calculated by an energization time calculation device 13, water feeding temperature Ti, hot water storage tank capacity Vt, and a rated consumption power W of the heater 5. In turn, when the hot water temperature becomes To by a temperature sensor 9, an energization for the heater 5 is turned OFF, a calculation of the energization time measuring device 16 is terminated, the energized actual data HG is fed to the memory device 12 to revise the data of the desired pattern in the input device 17.
HARA KAZUO
ITOU YOSHIKAZU
