The water heater should be cleaned every 2-3 years. Too frequent and prolonged time are inappropriate, which will affect the use effect of water heater. Solar water heaters need to be cleaned every two or three years. External cleaning: Solar water heaters need to wipe the dust on the surface according to the dirt. Keeping clean can maintain a high heat collection efficiency. Internal cleaning: open the water inlet of the solar water heater, pour the white vinegar into the water storage tank, let the water heater automatically circulate for 20 ~ 30 minutes, then open the water outlet to discharge the white vinegar after scale cleaning, then fill the water tank with water and drain after circulation. In daily life, everyone should pay attention when exercising solar water heaters. When the water temperature of the water tank is lower than 75 degrees, it is not easy to produce scale. Therefore, summer or spring and autumn depends on the weather. If there is enough sunshine, the water in the water tank will be added as needed, so that the water temperature will drop with the injection of tap water to avoid the generation of scale.