Water heater system including upper pipes and lower pipes

A water heater system including upper pipes and lower pipes comprising:

• an upper direct water inlet which is combined to the upper part of a housing and is connected to a direct water pipe while being opened so that direct-supplied water may be entered therethrough or is connected to an direct water pipe while being closed so that direct-supplied water may not be entered therethrough;
• a lower direct water inlet which is combined to the lower part of the housing and is connected to a direct water pipe while being opened so that direct-supplied water may be entered therethrough or is connected to an direct water pipe while being closed so that direct-supplied water may not be entered therethrough;
• an upper hot water outlet which is combined to the upper part of the housing and is connected to one side of a hot water pipe while being opened so that hot water may be discharged therethrough or is connected to one side of the hot water pipe while being closed so that hot water may not be entered therethrough;
• a lower hot water outlet which is combined to the lower part of the housing and is connected to one side of the hot water pipe while being opened so that hot water may be discharged therethrough or is connected to one side of the hot water pipe while being closed so that hot water may not be entered therethrough;
• an upper hot water return hole which is combined to the upper part of the housing and is connected to the other side of the hot water pipe while being opened so that disused hot water from hot water discharged through the upper hot water outlet may be entered therethrough or is connected to the other side of the hot water pipe while being closed so that disused hot water may not be entered therethrough;
• a lower hot water return hole which is combined to the lower part of the housing and is connected to the other side of the hot water pipe while being opened so that disused hot water from hot water discharged through the lower hot water outlet may be entered therethrough or is connected to the other side of the hot water pipe while being closed so that disused hot water may not be entered therethrough;
• a first connection pipe connecting between the upper direct water inlet and the lower direct water inlet;
• a second connection pipe connecting between the upper hot water outlet and the lower hot water outlet;
• a third connection pipe connecting between the upper hot water return hole and the lower hot water return hole;
• a heat exchanger connected to the first connection pipe to raise the temperature of direct-supplied water entered from the first connection pipe and to discharge hot water through an outlet;
• a buffer tank which stores hot water discharged from the heat exchanger in a state that scale or foreign substances included in the hot water is filtered and discharges the stored hot water to the second connection pipe through the outlet;
• and
• a bypass pipe connecting between the first connection pipe, the second connection pipe, and the third connection pipe.