The answer to 'shut-off valve slow draining' is that a slow-draining shut-off valve is often caused by a buildup of sediment or mineral deposits inside the valve. This can restrict water flow and lead to slow drainage. Common symptoms include difficulty turning the valve, dripping water, or water backing up when the valve is closed.
The solution typically involves removing the valve, disassembling it, and cleaning out any debris or buildup inside. This may require replacing worn washers or seals as well. If the valve is severely corroded or damaged, it may need to be replaced entirely. For DIY homeowners, this is generally a manageable repair, but if you are uncomfortable working with plumbing valves, it's best to call a professional plumber to handle the job.