Locating and Operating Your Main Water Shut-Off Valve

Locating and Operating Your Main Water Shut-Off Valve

Knowing how and where to shut off your home’s main water supply is as important as knowing how and where to turn-off or reset an electric breaker or replace a fuse.

Every home was required to have a main water shut-off valve installed inside the home during initial construction. So for most emergencies or repairs, shutting-off the proper inside valve will be our focus of this notice.

There are also underground shut-off valves installed at the property line; if shutting-off this valve is necessary, please call on a registered master plumber or WSSC to work this valve.

Background

It is important to understand that different plumbing arrangements will dictate where the proper main supply valve is located:

  1. Some homes have the water meter located inside, while others are located outside, underground within a “pit” at or near the property line or right-of-way. Some homes also have submeters, they are typically inside even if the main meter is outside/underground.
  2. Newer homes have fire sprinkler systems, while older ones generally do not.
  3. Home construction also differs greatly; basements, crawl-spaces, and slab-on-grade.
  4. Water shut-off valves may have round “wheel” handles or lever handles.

Locating the proper valve

A. Basements – the shut-off valve is typically located near the front foundation wall. The main water may have come through the concrete floor or through the wall. The valve is typically within 3-5 feet of where the main water enters. In some cases, the main water may enter in a different area, like a mechanical room, up through the floor, near the water heater or furnace.

B. Crawl-space plus a basement – the shut-off valve may be where the water enters the basement or in some older homes, the shut-off may be inside the crawl space. If the latter is true, you may want to consider a secondary valve located in the basement.

C.) Crawl-space with no basement – the shut off valve will typically be located near the water heater or under the kitchen sink, but anywhere is possible. As with “B” above, it may be inside the crawl-space; in which case, you may want to consider a secondary valve located up in the living space (near the water heater or under a sink).

D. Slab-on-grade construction – the shut-off valve will typically be located near the water heater or under the kitchen sink, but anywhere is possible.

Choosing the proper valve to operate

If you home has a fire sprinkler system, care is needed when selecting a shut-off valve. Unless it is a sprinkler pipe which is leaking, you should only shut-off the home’s plumbing supply and leave the sprinkler piping charged/live.

If the water shut-down is for a broken sprinkler line or sprinkler head than locate the 1st valve (closest to the main water line entry point) and operate that valve as described below.

For all other general plumbing shut-offs, emergency and non-emergency:

  1. For homes with fire sprinklers and an inside main water meter, locate and operate the 2nd valve, it will be above the main meter and past (downstream) of the fire sprinkler system “tee”. If you have a submeter, its 2nd valve will only isolate the irrigation and/or hose bibbs.
  2. For homes with fire sprinklers and an outside main water meter, locate and operate the 2nd valve, it will be past (downstream) of the fire sprinkler “tee”.
  3. For homes without fire sprinklers and with an inside main water meter, either valve will shut-off supply to the home, but operating the 2nd valve is a good practice and a safeguard if you are unsure of whether your home has fire sprinklers or not.
  4. For homes without fire sprinklers and with an outside main water meter, you will likely only have one shut-off valve that will shut down the entire home.

Closing the main valve (Shut-off/Turn-off)

A.) Round “wheel” handle valves will turn-off by turning the handle to the right (clockwise). It may take 2 or more full revolutions.

B.) Slowly turn level handle valves ¼ turn, until the handle it not parallel with the pipe. It should stop at a ¼ turn.

C.) Open a tub or sink faucet (hot & cold), on the highest level to relieve pressure and watch that spout to ensure a full shut-down. Then continue to open faucets throughout the home to drain-down as needed.

D.) If draining down home, be sure to de-energize the water heater and boiler where applicable by shutting off power to electric water heaters and any type of boiler. For gas water heaters, turn thermostat down to the pilot only setting; if you drain the heater, shut off the gas.

Opening the main valve (Open/Turn-on)

  1. Close all faucets except a tub or sink on the highest level.
  2. Partially turn-on valves slowly; extra slow for lever handles; stop after ½ revolution on wheel handle, ½ of a ¼ turn for lever handle; with water flowing, slowly turn-off highest open faucet.
  3. Listen for water pressure to equalize (noise ends); fully open main valve. Bleed air from lines by slowly opening (hot and cold) on all faucets, one at a time, until air stops flowing, then close each faucet; move to all others until complete.
  4. Only turn power on to electric water heaters and boilers after the water system is full and all air has been bled-out. If gas was turned-off, carefully following re-starting direction on the appliance jacket or call a registered plumber or your gas company for service.
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