Stop taps are normally only used once in a while, often when there is a plumbing emergency. This means that often when you come to turn it you cannot as it as seized in the open position. If you need to shut off your stop tap and it is seized then you will have to use the main incoming stop tap that should be near the boundary of your property. If this is also seized then you will have to contact your local water supply company and get them to change it. You may need a stopcock key to isolate the stop tap located at the boundary.
Freeing a seized stop tap can be consuming and is not always possible, sometimes the only option is to replace the whole unit.
Firstly if you find that your stop tap has seized do not try and use brute force to close it just yet. Firstly give it a gentle spray with some light lubricating oil, leave this to penetrate for 10 minutes and then try and turn the handle again. Try turning the handle in both directions as this can often loosen the seized part.
Spray the penetrating oil down the shaft and where the gland nut is.
If the stop tap handle will still not move then remove the gland nut using a suitable spanner, this will turn anti-clockwise. Once it has been unscrewed, slide it down the shaft and then spray more light lubricating oil down the spindle. Allow this to soak in and repeat as necessary. If this does not work then try tapping it gently with an hammer. Failing that you can try to get some leverage with a large spanner, but be aware that it is easy to snap the spindle. If that happens then the stop tap will require replacing.
Even with the best tools in the world it is sometimes impossible to free a seized stop tap!
