stuck sink supply water valve

[Pico Rico]

you know, the valves under the sink. They are both stuck (open, fortunately). Is this a common problem? What is the solution? How do you prevent this from happening?

[bob haller]

I have been replacing all my valves with ball valves over time. makes futture service much easier

[hrhofmann]

A large pair of pliers should help. Try rocking the valve back and forth a tiny amount, gradually increasing theamount of rock. You can be a bit mor e vigorous if the valve stem is metal rather than the really cheap plastic that is becoming more common these days.