Residential Water Supply.

Your household water supply is either provided by a city water source or from a private well. Both sources are typically located in the basement or crawlspace. Homes built on slabs will have a utility room.

A private well is more complex than city provided water. It requires a source (well), a pump to pull water into a storage tank, and a pump to maintain pressure in the tank and water supply pipes. Private well systems are not covered here.

"City" water is provided from a central system maintained by government or commerical utility. Water is provided in a supply line that's connects a water main to a water meter in your home. The meter is usually the dividing point between the city-owned water lines and the homeowner's plumbing. In warmer climates, the meter may be outside but in cold areas it's typically in the basement or crawlspace.

Any problems with the water meter must be reported to the water company.

Residential plumbing systems typically use a 1/2" to 1" copper pipe that brings water into the home at a pressure of about 45-50 pounds per square inch (PSI). The supply pipe will have two shut-off valves. One is before the meter, and a second is after the meter. Some valves have a metal flange that require a pipe wrench to operate. This type of valve closes with just a quarter turn. If a wrench is required to close this valve, a correct size wrench should remain near the valve in case an emergency shutoff is required.

A well entry usually omits the meter and has only one shut off valve. The water supply pipe may be copper, plastic (CPVC - chlorinated polyvinyl chloride) or galvanized steel. After the meter, cold water lines branch out from the main pipe to the kitchen, bathrooms, and the water heater(s). Hot water pipes start at the water heater and go to the kitchen and bathrooms.

Additional shut off valves are typically located under each sink and toilet. Outdoor faucets typically have an inside shut off valve. You should know where the main and all other shut off valves are so you don't have to search for them if a leak occurs. Caution: Your water heater, and possibly other systems (such as a boiler for hot water heat) require a cold water supply. They can be damaged or create hazardous conditions if denied water. Be sure to check manufacturers instructions before turning off the cold water supply to such devices.