You now have a switching valve installed in the blue zone. “The switching valve is now switched to solar power, but there is no water in the nozzle.” This means that there is a problem with the switching valve and there is no communication in the solar direction. "Turn on the gas, there is water in the nozzle, but the nozzle is off, the gas does not turn off, and after a while, water will come out of the solar signal pipe filled with water." there is a problem with the switching valve and the gas water heater. The hot water outlet and the hot water outlet of the solar water heater are always connected. As long as the water inlet valve of the gas water heater is opened, the water will be heated by the gas water heater, and then pushed into the solar water heater through the hot water pipe of the heater -solar water, then will overflow through the solar system. water heater. It is recommended to replace it with two one-way valvess red which are more reliable.
In my experience, this is completely impossible. The water pressure is originally low, and all "pressure showers" rely on the principle of "small hole resistance" to pressurize. Smaller holes require greater pressure (squeeze) to release enough water. at home is too weak, and replacing it with a “booster shower” will only make things worse. I replaced it with a thicker pipe. Due to the enlarged "diameter" section, the water flow increased a little.