PURPOSE: To send forcibly and quickly hot-water reserved in a generating equipment and device to save fuel by a method wherein a conduit is connected between the generating equipment and device, generating hot-water or hot-air, and a restoring equipment and device while a quick sending pipe is fitted freely expandably into the conduit.

CONSTITUTION: In case the device is utilized by attaching to a bathtub 3, functioning as the storing equipment and device, the quick sending pipe 5 is extended into the bathtub so as to obtain a proper length by loosening a tightening device 6 at first and fixing it to secure the pipe 5 to the conduit 2. In this case, hot-water, heated in a boiler 1, flows quickly through the pipe 5 by extending the conduit 2 to the full length thereof, therefore, the length of the pipe 5 is adjusted so as to obtain a proper flow speed by observing the flow of hot-water. The hot-water, heated by the boiler 1, flows into the bathtub 3 quickly without loss and, therefore, hot bath water may be prepared quickly.