Everyone should know where the water main isolation valve is situated. Quick response in an emergency such as a burst pipe is essential. If you have to work on an appliance such as a dishwasher or icemaker, or you need to change a faucet, you have to first isolate the water supply. If the relevant kitchen or bathroom shutoff valve is faulty, you will need to shut off the main water supply first.
Locate the household water meter. This is outside at floor level where the water supply pipe enters the home or the basement.
Identify the main shutoff valve. There is a shutoff valve installed on both sides of the meter. One of the valves is situated between the meter and the house; the other is the primary water main shutoff valve used for isolating the water meter.
Turn the meter shutoff valve situated in front of the meter by turning the lever or wheel clockwise until it can't go any farther. The house water supply will then be safely shut off.
Switch off the pressure tank supply pump if the household water supply comes from a private well. The pressure tank is situated at the head of the well. If there is no local switch, locate the pump electricity supply breaker and turn it off.