Is there a solenoid valve or a manual valve? Solar power is very simple, a pipe is connected to a water pipe and water is added by tap water pressure. If you use the direct type, there will usually be a solenoid valve. Make sure the valve is in good condition; there should be no problems with the filter. If the manual valve can't be pushed up, I don't understand. Is it because the tap water pressure is too low or the solar installation is too high?
Touch the solenoid valve with your hand and press the water button. If you feel vibration, then the solenoid valve has an 80% chance of being good. If you do not feel any vibrations, then the solenoid valve is in good condition. 100% broken. Replace it. If you feel a vibration and there is no water supply, there are two possibilities
1. Water pressure is too low (if there is a booster pump). at home, this possibility is very low)
2. The solenoid valve is clogged. There is a water filter on the solenoid valve, and there is a hexagonal blocking cap under the solenoid valve. remove the filter and clean it