Linked hot water supply system

A linked hot water supply system, comprising:

• a plurality of combustion hot water supply devices arranged in parallel between a water supply pipe and a hot water supply pipe;
• and a controller, configured to change a number of operated units of the hot water supply devices to adjust a heating capacity in accordance with a hot water consumption,
• wherein the hot water supply devices is each provided with a water supply flow rate sensor, a bypass flow rate adjustment valve, a hot water outlet flow rate adjustment valve and an inlet water filter installed to an introduction part of tap water from the water supply pipe, wherein the hot water outlet flow rate adjustment valve of each hot water supply device is configured to adjust the water passing volume of the respective hot water supply device by adjusting its opening degree during operation,
• wherein the controller is further configured to calculate a water passing volume of each hot water supply device based on a detected flow rate of the water supply flow rate sensor, an opening degree of the bypass flow rate adjustment valve, and an opening degree of the hot water outlet flow rate adjustment valve,
• wherein when the hot water supply devices are operating at a same time and an opening degree of the hot water outlet flow rate adjustment valve of a last operated hot water supply device among the hot water supply devices in operation is at maximum, the controller makes a determination on blockage of the inlet water filter installed in each of the hot water supply devices by comparing the water passing volumes of the hot water supply devices in operation.