Generally, the closing direction of manual water supply of solar water heater should be counterclockwise. That is to say, when you need to turn off the solar water heater to manually fill the water, you need to turn the valve or switch to the left until it is completely closed. However, there may be differences between different solar water heater models. Therefore, during specific operation, it is recommended to carefully read the solar water heater instruction manual to ensure that the manual water supply is properly cut off.
If you don't understand, use a stupid method. Find the water inlet valves for both water heaters and close them. If you open the tap at a certain time and there is no water coming out, that means both valves are closed, so just use which water heater to open the vanno water from this water heater. First you need to find the water inlet valve of the electric water heater and the solar water inlet valve that should be used. to open which valve? The other valve must be closed, otherwise the water will flow