Water heater

Abstract

A water heater includes a tank and a heating pipe. The tank has a water storage space therein. A bottom of the tank is provided with a cold water inlet and a circulation outlet. The tank is provided with a hot water outlet located at a position not less than one half height of the tank. The heating pipe is connected with a circulation pipe outside the tank to communicate with the circulation outlet. The heating pipe extends upward from the bottom of the tank into the water storage space. The heating pipe is provided with an opening facing sideways. The opening is located at a certain height of the water storage space. An outside of the heating pipe is provided with a heating device for heating the heating pipe.

What is claimed is: 
     
         1 . A water heater, comprising:
 a tank, having a water storage space therein, a bottom of the tank being provided with a cold water inlet and a circulation outlet, the tank being provided with a hot water outlet located at a first position not less than one half height of the tank;   a heating pipe, extending upward from the bottom of the tank into the water storage space, the heating pipe being provided with an opening facing sideways, the opening being located at a certain height of the water storage space; the heating pipe being connected with a circulation pipe outside the tank to communicate with the circulation outlet; an outside of the heating pipe being provided with a heating device for heating the heating pipe.   
     
     
         2 . The water heater is claimed in  claim 1 , wherein the heating pipe extends upward in the water storage space to a second position not less than one half height of the water storage space; and
 the opening is located at a third position not less than one half height of the water storage space.   
     
     
         3 . The water heater is claimed in  claim 1 , wherein one end of the heating pipe is bent sideways to form a bent section, and the opening is located at a distal end of the bent section. 
     
     
         4 . The water heater is claimed in  claim 1 , wherein the cold water inlet is provided with a cold water control valve, and the hot water outlet is provided with a hot water control valve. 
     
     
         5 . The water heater is claimed in  claim 4 , wherein a water level sensing unit is provided in the water storage space and electrically connected to the cold water control valve.