My sprinkler system that was installed back in the Spring has not been used for over a month since it is winter and because we have water restrictions here in NC. Back in October I disconnected the water supply line to the valve manifold which sits inside of a valve box and left it disconnected as part of my winterization of the system. Yesterday, I opened the valve box and noticed that there is a good amount of moisture in the box, especially underneath the box lid. The valve box is a plastic box. Is it common for these boxes to have alot of condensate build up? Is there something I should do to lessen or prevent it? Can this damage the solenoids on the manifold valves?