My cold water shut-off valve is stuck in the "open" position. I have tried WD-40 , also vinegar to loosen. No luck. Any suggestions?
You may want to try using some "penetrating" lubricants, available in most hardware stores. Whatever you do, be careful not to apply too much force to the valve. If the valve is stuck, the pipes are likely to be old and brittle. If these are galvanized pipes and you are also experiencing some low water flow, it may be time to think about replacing the pipes with copper lines and a new shut off valve.
Isn't home improvement wonderful, you start with a simple problem and before you know it you are into a major remodeling project. - George