Shut-off valves (also known as angle stops or stop valves) are located throughout the house. Typically they are installed in-line of all hot and cold water supply lines connected to a plumbing fixture such as faucets in the kitchen, bathroom, laundry room and hose bibbs. Shut-off valves are also located in water lines supplying dishwashers, ice makers, washing machines, toilets and the hot water tank. Many older homes didn't have shut-off valves installed when they were built. I live in a 1969 home and, over the years, shut-off valves were only added when making plumbing repairs and during renovations. The absence of shut-off valves in my own home was not an exception. During my 28 years as a pre-purchase building inspector I have seen thousands of homes without shut-off valves.
The valves are usually tucked away in an unobtrusive location and we only start looking for them when it becomes necessary to shut off the water supply.
By the time we want to close the shut-off valve it has been in the open position for many years. During this time minerals in the water have accumulated around the stem of the valve and have hardened. Hard water deposits make it difficult or even impossible to close the shut-off valve.
- Stuck valves can sometimes be freed
- Maintain shut-off valves to prevent a build-up of mineral deposits.

HOW TO OPEN A STICKY OR STUCK SHUT-OFF VALVE
RULE 1: Close the wain water supply valve and drain the plumbing system. If things go wrong you will not flood the house.
RULE 2: Cover the floor with as many old towels (not rags) as possible to catch any water left in the pipes after you have shut off the water. If things go wrong only a minimum amount of water will escape.
RULE 3: Do not use force. Trying to force something to do what it does not want to do is a recipe for disaster, especially when it comes to trying to open a stuck shut-off valve. Using too much force may break the supply pipe to which the shut-off valve is attached.
- Try loosening the shut-off valve by spraying the valve stem and bonnet nut with WD-40, Pb blaster or similar product.
- Try loosening the bonnet nut slightly with an adjustable wrench. Once the handle and stem loosen up, you may have to re-tighten the bonnet nut slightly if it starts to leak a little.
- In the event that you are not able to close the valve you will have to install a new shut-off valve. Most of the new brass or chrome plated brass valves contain lead. Check the package for lead rating. Click here for more information on lead in brass fittings.

REGULAR MAINTENANCE
Make a check list of all shut-off valve locations in your home and store it with the back-up batteries for smoke alarms. Whenever it is time to change batteries in the alarms, take the list out and open and close all shut-off valves several times. This will prevent a build-up of minerals and keep your shut-off valves operational. In the event of an emergency when you have to turn off the water supply, you will be forever thankful that you took the time for this simple annual maintenance routine.

WARNING
Never use too much force when trying to close a stuck shut-off valve. You can damage the valve, or break it and cause a water flood.