shut off main water supply Archives - BobsPlumbingVideos.com

If you’re ever faced with doing a simple plumbing repair that requires shutting off the water, my advice is always go to the point of use emergency water shut-off valves located under your kitchen or bathroom sink or under your toilet tank.

These are convenient and easy to access and what I always reach for when attempting a repair. The question is what do you do when these don’t work?

Well you’re going to have to shut off the main water supply that enters the building and drain the entire system down into the lowest fixture located in your home.

Now the location of the water service entering a building will vary depending what part of the country you’re located.

Here in New York City they generally enter the front facing portion of the building down in a basement either through the wall and in some cases at ground level located in a pit along with the access covers to the building house drain.

The procedure I follow is to locate the main valve which is a few feet after entering the building and turn it in a clockwise fashion until it stops.

A word of caution, don’t force it beyond the stopping point, these valves are often very old and if you break it in the closed position you’ll be in for some EXPENSIVE plumbing repair.
I’ll then open up a fixture on the lowest floor of the building, and then go to top floor and open a fixture allowing the entire building to drain down.

A substitute for that main water valve could be the quarter turn ball valves that are sometimes located on the inlet and outlet of your water meter.

If you have them and your main shut-off valve is very old, I say go for it!

Now that the system is shut down, it’s time to replace all those emergency water points of use shut off valves that aren’t functioning.

When you’re done it’s time to close the lowest fixture off and then slowly turn on the water supply allowing the air to purge from the system from that fixture you left open on the top floor.