In the first case, the solar water tank is filled with water. Since cold water is required to fill the water tank, the water meter must of course be turned.
In the second case, solar energy is a pressurized water reservoir. While the hot water is drained, the cold water should be replenished at the same time and the water meter should be turned on.
In the third situation, when taking a bath, the solar hot water flows from the hot water pipe, and the temperature regulating valve should be used to take a bath, so that the cold water is turned on at this time (when cold water and hot water are mixed), and the water meter is running.