How to open the exhaust valve of floor heating separator?

The exhaust valve of the floor heating water separator needs to close all other valves of the floor heating first, and then open them in a certain order. Otherwise, the exhaust valve can only discharge heating water, not internal gas, and can be opened only by rotating counterclockwise. The specific operation steps are as follows:

1. Close all valves on the floor heating valve group, including the main valve, branch valve and bleed valve. ?

2. Open the main inlet valve and branch inlet valve. ?

3. Open the backwater bleeder valve. ?

4. Open the first branch valve of backwater. ?

5. When the backwater exhaust valve flows out of clear water without bubbles, open the second valve. ?

6. Open the other branch valves in the same way. ?

7. Finally, when opening the main backwater valve, close the backwater bleeder valve to complete the operation. ?