Turn off the water off inside your home
First of all you need to turn off the water supply to all water faucets in your home. Then carefully listen for dripping sound. Remember to stop your wife or other house members not to open the water until you find the leak.
Find out the main water meter
Then you need to seek the main water meter of your house. It is usually located near the street and placed inside a box. This box is usually made of metal or plastic and is placed around three inches below the ground. You can see water written on the lid of the box.
Record the numbers
After locating the main water meter, you need to open and jolt down the numbers written on the meter. Remember to recheck that water is turned off from all the appliances and faucets before noting the reading. Now wait for almost half an hour before checking the meter reading again. If the numbers are increased then there is a leak in your house.
Turn off the main water supply
Turn off the main water supply of your house. You need to turn off the main water cut-off valve which is a valve connected the plumbing of your house. You need to manually turn it off by turning it right. This valve is most commonly found under the house.
Check the reading
After turning off the main water cut-off valve, you need to note down the readings once again. If it stops then the leak is in your house. In case the meter readings are increased again then there is a leak outside your house. The leak is located in the pipe linking the water meter and your house.
Turn on the main water supply
In case the leak is inside your house, you need to turn on the main water cut-off valve. Then turn off the main water supply towards toilets, water heaters and other appliances.
Check the meter again
You need to check the meter reading again. If the numbers are same then you need to turn on water cut-off valves turn by turn. Check the reading after turning valve on for one appliance or fixture at a time. When the numbers move again then you will find your leak.