U-tube solar collector is a new type of new energy-saving product. The collector and the water tank are separated by the heat transfer medium in the U-tube to convert the solar radiation energy into heat energy and transfer it to the water tank through the heat exchanger. The solar collector can be designed, constructed, and inspected simultaneously with the indoor water supply and drainage system, and put into use at the same time as the construction project, so that it can meet the requirements of energy saving, environmental protection, safety, beauty, and economy. U-tube solar collectors are installed in two ways: one is mounted on a flat roof. The other is installed on an overhead roof.