Patent ID: 8868251

Claim:
A hot water supply system that supplies hot water, comprising: a first water heater that includes a storage unit storing at least device information including information for identifying a priority device that controls the first water heater and a second water heater, and a device number of the second water heater, sets the first water heater as the priority device based on the device information, and performs hot water supply control by which the first water heater cooperates with the second water heater, according to a hot water supply request; the second water heater that is connected to the first water heater in parallel, and supplies hot water according to the hot water supply control by the first water heater; communication connection means that communicably connects the first water heater and the second water heater; water supply means that supplies water to the first water heater and the second water heater; and hot water supply means that supplies hot water heated by the first water heater and hot water heated by the second water heater to a hot water supply destination, wherein if the first water heater is in an anomaly state or if continuous operating time of the first water heater is over a predetermined time, the first water heater selects the second water heater, which is operating, and sets the second water heater as the priority device, wherein each of the first water heater and the second water heater includes: a heat exchanger that heats flowing water by combustion of a burner, a water flow valve that switches a flow of supplied water, an incoming water flow sensor that detects a flow rate of the supplied water, an inlet temperature sensor that detects inlet water temperature of the supplied water, upstream of the heat exchanger, an output temperature sensor that detects outgoing water temperature of the supplied water, which is heated, downstream of the heat exchanger, timer means that counts operating time of each of the first water heater and the second water heater, and a control unit that controls the combustion of the burner or a supplied flow of the supplied water based on at least the flow rate of the supplied water, which is detected, the inlet water temperature, which is detected, the outgoing hot water temperature, which is detected, and setting temperature, wherein the control unit of the first water heater increases or decreases a number of operating water heaters based on the flow rate detected by the incoming water flow sensor disposed at the first water heater, and wherein if there is a water heater whose continuous operating time is over a predetermined time, the first water heater determines a water heater to be stopped after a number of operating water heaters is increased and the flow rate detected by the incoming water flow sensor is reduced.