| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a water heater dispensing with a water stop valve disposed in a pipe communicating a heating means with a tank. <P>SOLUTION: This water heater 1 is switched to any of a first state for blocking off the circulation of water among the tank, a return pipe and a drain pipe, a second state for circulating the water between the tank and the return pipe, and blocking off the circulation of water between the tank and the drain pipe, and a third state for circulating the water between the tank and the drain pipe and blocking off the circulation of water between the tank and the return pipe by a three-way valve 38. As a result, two water stop valves necessary for a conventional water heater can be eliminated, and the labor hour for a construction work can be reduced. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
