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This article describes The Main Water Shutoff Valve or Control, How to Locate & Shut Off Water in a Building. Readers of this document should also see Water pump and pressure tank repair diagnosis & cost an specific case which offers an example of diagnosis of loss of water pressure, loss of water, and analyzes the actual repair cost.

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MAIN WATER SHUTOFF VALVE - How to Find the Valve and How to Turn Off Water in a Building

Lever type water tank shutoff valves: Every private pump, water tank, and well system should have at least one main water shutoff valve. Usually the valve is located close to the water pressure tank, on the main water line leaving the water tank (and supplying water to the building). In this photo the blue handled valve which we labeled "WATER" is connected on the water tank bottom outlet fitting on the left side in this picture. We like these lever type valves as they are more reliable and less leaky over time than the older round-handled valves (discussed next) that just use an internal washer to close off the water supply.

Round handled water tank shutoff valves are used on many water systems. In this photo of an older type galvanized steel water pressure tank we see a blue jet pump to the left of the tank and we can just make out a galvanized pipe leaving the top of the water pump and (probably) entering the water tank on the back side that we can't see. At the right side of this water tank, starting near the bottom, we see first a tank drain valve (see that white tape on the drain valve's outlet where someone has recently attached a hose?). Just above the tank drain valve we see a round-handled shutoff valve. This will be the main water shutoff for this building. We also notice a copper wire connected to the water tank piping, probably someone's attempt to either ground the plumbing (electrically) or to provide a connection to ground for the service panel. (This won't work to provide a connection to earth for the electrical panel if the well piping is plastic.) At the right side of this water tank we also notice an air volume control (that disc-shaped device) and a copper tube connected to the right side of the air volume control (AVC) reappears but is hard to see, connected to the water pump itself.

Which way to turn the water shutoff valve - which way is "off"?

Lever type water valves such as the one in this photo are "on" or "open" permitting water to flow when the valve handle is parallel or "in line with" the water piping, and the valve is "off" or "closed" or "shut" when the valve is at right angles to the piping. So in this photo you can see that the water valve is in the "open" position.

Round handled shutoff valves are in their "open" position when the valve has been turned fully counter clockwise and these valves are "shut" when the valve has been turned fully in a clockwise direction.

Multiple Water Shutoff Valves May Be Present

Multiple water shutoff valves may be present especially on older water systems. An owner or plumber may decide it's less work to leave an old valve, one that won't shut off, in place and simply install another one. In this photo of a rather ugly water tank and well installation, we can see three different water shutoff valves. A yellow handled lever type shutoff valve is installed on the copper pipe leaving the bottom of the water tank - photo center An older round handled shutoff valve is visible just to the left of the gray-covered pump pressure control switch (follow the copper pipe from the center bottom of the water tank, past the yellow handled valve, past the left turn (or elbow), through the pressure control switch, to the left of the switch and where galvanized piping begins. A still older shutoff valve, without its handle, is visible at the other end of this section of galvanized (silver colored) piping, just before the copper piping begins again.

How to Fix Leaky Water Shutoff Valves

Leaks at main shutoff valves occur, particularly at round shutoff valves around the valve stem (the rod just under the valve handle). Sometimes you can repair such a leak by carefully and gently tightening the nut that is found just under the round valve handle and through which the valve stem protrudes. This will squeeze valve stem packing more tightly around the stem and may stop a leak there. But be careful not to over do it - if you crack the packing nut or break the valve assembly you'll have a much bigger leak.

How to turn off the water if you cannot find the main shutoff valve: if the main shutoff valve can't be located, or if it is broken (or you just broke it), or if it is jammed and does not turn, you can still stop water from running into the building. Find and turn off the electrical power to the water pump. The water pump main electrical switch is usually located near the water pump or water pressure tank (if the pump is a submersible unit down in the well). The water pump electrical switch is described in more detail below.

If you turn off electrical power to the water pump, some water may continue to flow into the building until all of the pressure in the water pressure tank has been exhausted (perhaps one to four minutes) but that'll be it.

If your water supply is from a municipal supply and not a private well and water tank, and if your water shutoff needs repair or replacement, you'll need to find (or get help finding) a main water shutoff that may be located (buried) between the building and the water main in the street. We advise against taking apart or messing with a stiff or leaky main water shutoff on municipal water supply systems unless you can shut off the water outside of the building first.

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PLUMBING TOPICS
OIL TANKS
SEPTIC SYSTEMS
WATER PRESSURE REGULATOR ADJUST
WATER PRESSURE REPAIR GUIDE & COSTS
WATER PRESSURE LOSS DIAGNOSIS GUIDE
WATER PRESSURE & FLOW MEASUREMENT
  WATER PUMP PRESSURE CONTROL ADJUSTMENT
  WATER PUMP PRESSURE CONTROL REPAIR
  WATER PRESSURE REGULATOR ADJUST
WATER PUMPS & WELL TANKS
WATER PUMP CONTROLS & SWITCHES
  IDENTIFY WELL PUMP TANK COMPONENTS
  MAIN WATER SHUTOFF VALVE
  WATER PUMP ELECTRICAL SWITCHES
  WATER PUMP PRESSURE CONTROL
    WATER PUMP PRESSURE CONTROL ADJUSTMENT
    WATER PUMP PRESSURE CONTROL REPAIR
    WATER PUMP PRESSURE CONTROL REPLACE
  WATER PRESSURE REGULATOR ADJUST
  WATER PUMP RELAY SWITCH
  WATER TANK AIR VOLUME CONTROLS
  TANK AIR INLET VALVE
  TANK AIR VALVE REPAIRS
  WATER TANK PRESSURE GAUGE
  WATER TANK DRAIN VALVE
  WATER TANK RELIEF VALVE
  CHECK VALVES
  WATER FILTERS
  WATER FILTERS
WATER PUMP TYPES & LIFE EXPECTANCY
WATER PUMP & TANK SAFETY
WATER SUPPLY & DRAIN PIPING
WATER TANK TYPES: WATER, OIL, EXPANSION, ALL
WATER TANK LIFE EXPECTANCY
WATER TANK REPAIRS
WATER TANK AIR, HOW TO ADD
WATER TANK BLADDERS & CAPTIVE AIR
WATER TANK BLADDER PRESSURE ADJUSTMENT
WATER TANK PRESSURE CALCULATIONS
WATER TANK SIZE & VOLUME
WATER TANKS HOW THEY WORK
WATER TESTING
WATER TREATMENT EQUIPMENT CHOICES
WELLS CISTERNS & SPRINGS
WELL, PUMP, TANK LIFE EXPECTANCY

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