Temperature difference circulation type 
Cold water enters the solar water heater through the automatic water supply control box, and the vacuum tube selectively absorbs solar energy through the film layer to raise the temperature of the cold water. The collector and the storage tank have temperature sensors respectively. When the temperature difference between the collector and the storage tank reaches the set value, the circulation pump is started to push the hot water in the collector into the storage tank for insulation, and at the same time, the low-temperature water in the storage tank is sent to the collector for heating. This cycle repeats itself to achieve the purpose of heating the water in the system. 
Series parallel type 
Cold water enters the solar water heater through an electromagnetic valve, and the vacuum tube selectively absorbs the film layer to convert light energy into heat energy, causing the cold water to heat up. Users can determine the water temperature in the solar water heater by installing a temperature sensor and display device. When the water temperature reaches the bathing temperature, the hot water valve can be opened to access hot water. 
Constant temperature water discharge type 
Cold water enters the solar water heater through the upper water control box, and the vacuum tube selectively absorbs the film layer to absorb light energy and raise the temperature of the cold water. The collector and the storage tank are respectively equipped with temperature sensors. When the temperature difference of the collector reaches the set value, the circulation pump or solenoid valve is started to push the hot water in the collector into the storage tank for insulation.