the middle line going to the booster pump (which no longer works nor do I use anymore) valve is closed. Will this line freeze if water isn’t moving though it? It has been left closed in freezing weather the past 2 or 3 years. Just want to be safe. Would really be great to have this return move water in the pool. FYI the booster pump is broken at the bottom and shoots water out when I open the valve so I’m not sure what I need to do. Freezing temps will be here by Saturday.