Locating and closing the correct main shut off valve for a house water service is something that requires some knowledge and some care. Many times this seemingly simple task has resulted in a property owner left with no water service for their premises.
In other cases mishandling a water valve has resulted in the need for a major water main repair. Following some simple instructions can save a lot of aggravation, money, or having to call a plumber to do a costly water line repair.
Locating the main control valve
The main control valve for a house is typically located on the inside front wall of the basement or inside an access pit closest to the public roadway. Sometimes there may be a cabinet with an access door built around the main valve.
In NYC most houses and properties now have water meters installed and there are two shut offs present. There would be one valve on the street-side of the meter, and one on the house-side of the meter.
Which valve should you close?
Whenever there are two main valves present always close the one closest to the inside of the house. This is most important because if the valve is faulty or breaks then the street-side valve acts as a back-up and allows for the other water valve to be repaired easily.
On the other hand if the street-side valve is used and breaks or is faulty the roadway may have to be opened to do a water main repair. Never operate the street side valve unless there is no other option.
How to close the main control valve
Most main valves are now of the ball type variety. They are as a rule the most dependable and easy to operate. Since the mechanism to operate the device is a bored out metal ball only 1/4 of a turn of the handle closes the water to the house. There is usually a directional handle to instruct you on which direction to turn the handle on a ball valve.
In the case of a gate valve numerous clock-wise turns will be required. The number of turns depends on the size of the valve. Extra care must be taken with a gate valve as there is a stem that connects the handle to the gate. The stem of a valve can be broken unless care is taken. Always apply even pressure to turn the handle, never jerk a main control valve or use excessive force.
If the stem snaps the shut off valve becomes non-operational. If the stem snaps with the gate in the closed position a main valve cannot be repaired and water main service will be interrupted.
The importance of a high quality valve
A typical high quality main valve (shut off valve) costs a water main contractor less then $15.00 and should last for decades if it is not abused. Frequently just a visual inspection can determine if one valve is better than another – it may have a thicker stem, or a heavier body. Most importantly every valve has a rating clearly written on it’s side.
There is no reason to skimp on this vital item to save a couple of dollars. Balls valves have proven to be much more reliable and trouble free than typical gate valves.
The NYC DEP code requires ball valves to be full-port opening valves, which do not restrict the flow of water into the property. Saving a dollar or two on a ball valve that restricts the flow of water makes no sense when considering which shut off valve to install as the main valve. For more sewer and water line information visit the Sewer and Water Main Resources Page.