| 摘要 |
PROBLEM TO BE SOLVED: To provide a water heater capable of discharging expanded water to the outside of a system while reducing heat loss.SOLUTION: A water heater includes: upper flow channels b9, b10 connected to an upper portion of a tank at one side ends and connected to a relief valve 26 at the another side ends; a first check valve 25a disposed in the upper flow channels; lower flow channels b5, b4, b6, b10 respectively connected to a lower portion of the hot water storage tank 21 at one side ends and connected to the upper flow chanel at a downstream side with respect to the first check valve 25a, at the another side ends; flow channel switching means 23a for communicating or disconnecting the upper flow channels and the lower flow channels; and first bypass flow channels c1-c4 connected to the upper flow channel at an upstream side with respect to the first check valve 25a at one side ends, and connected to the lower portion of the hot water storage tank 21 at the another side ends. A primary-side heat transfer tube constituting a part of the first bypass flow channels c1-c4, and a secondary-side heat transfer tube in which water to be heated flows, are disposed in a state that heat can be exchanged therebetween. |
