We use those Blue Rhino propane tanks for our grill that you get at Home Depot by paying a deposit and then trade in when they are empty. The one that we're currently using won't shut off. The valve seems to be broken. Two questions. One, is this a big deal? We grill maybe once a week so it probably has a couple of month's worth of propane left in it. Second, once it's empty I assume it won't really be empty, just too low pressure to function. Will it be a problem when I disconnect it from the grill at that point?