Hello, I am closing our pool and have a check valve prior the pump. I am attaching a similar setup in a picture drawing. The question is, how can I airlock my Pool return If I am blowing via the pump with an air compressor? I left Multiport valve from filter in "Winterize" setting and I believe when I place it in that position there is really not a closed system but it is "open". Also when unplugin the aircompressor, all air pressure will be gone.
Perhaps there a special cap for the check valve I can use that allows airlock between the check valve and Pool returns?
Thanks for your help.