The most common location for the master valve in your house or apartment (have your apartment superintendent show you how to do this) are:
- where the water supply enters your home
- near your clothes-washer hook-up
- near your water heater
To determine if the valve is the correct one, turn it off and see if it shuts off all water faucets in your home. If not, repeat this process with each valve until you find the correct one. If you are unable to find it, or it is inoperable, contact a plumber for assistance. Once you've found the valve, mark it with something distinctive like bright paint, a tag or a ribbon so you can locate it quickly in case of an emergency.