Locating The Valve- This is usually located behind the toilet itself, where the pipes connect to the wall. You will recognize this as a football shaped flat valve connected to a hose or pipe on the bottom of the toilet.
Turning Off The Valve- To turn off the shut off valve, turn clockwise until you cannot turn anymore. This will shut off the water supply to the toilet, and can be the quickest method of doing so – something that is important during a crisis.
Rusted Or Tight Valves- If the valve looks rusty, or if it is just difficult to turn, then try applying some WD-40. For those who don’t know, this is industrial lubricant spray, and can be purchased from almost any hardware store. This should lubricate the valve enough to give it some play, allowing you to turn it off.
Testing The Water- To do this, flush the toilet. If the water has been turned off, then the water in the back tank will enter the toilet bowl, but will not refill afterwards like normal. However, if your toilet is clogged, you can test to see if the water is off by opening the back tank and checking the small lever in the water.
Turn The Valve Again- To turn the water back on afterwards, remember to turn the valve counterclockwise. This will make sure that the toilet is functional and ready for future use.
Finding The Valve- The location of this valve tends to differ, depending on the climate you live in. If you live in a colder climate, then the valve is usually located in a cellar or basement where it can avoid freezing.
Identifying The Valve- The main shut off valve will usually consist of one or two wheel handles or lever handles, located either above or beside a metal pipe. These will probably be either side of the water meter, or, if you have an external water meter on the side of your home, there is a good chance that it will be in a close proximity to this.
Shutting It Off- To shut off the main water supply, turn the handle clockwise. If there are indeed two wheel handles (or lever handles), then turn the one closest to your home to turn off the water.
Propping The Float- You can prop the float with a piece of wood, or block that is large or long enough to keep the float high up in the tank. For the best results, use a piece of wood that is roughly one inch shorter than the height of the tank itself.
Drain The Water- If you have the ability to flush the toilet, then do so. This will drain the excess water from the tank, while the wood or wire maintain the height of the float, ensuring that no more water enters the back tank.
Refilling The Tank- To refill the back tank and get the water back to where it should be, simply remove the wood or prop device you have used, allowing the float to drop, which will signal to the system that more water needs to be allowed inside.