A little help please. I am trying to install a 4x20 Solar Heater on the garage roof next to the pool. Height is only 7 feet and garage roof is only 1/12 pitch so I want to mount the panels flat to the roof. As well I am hard piping it in and I was planning to mount the valve about 3 feet up the wall. This will leave me some room to install the SWG cell when it arrives. I need the valve so I won't use the panels at night. A 2-way valve came with the kit. However, the instructions seen to suggest installing the 2 way between the lines "going to" and "coming from" the heater which makes sense to me. My concern is: It seems to me that with the 2-way valve installed between the lines either up the wall or on the ground it will allow for the panels to bleed off when I open the valve thus having to reprime the panels daily. Question. Is my thinking of bleed off correct, is there a better location to install, and should I think about a couple of check valves to help? Thanks in advance for the help. Dave S.