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How to Shut Off Water in a Plumbing Emergency

Water Leaks


The most common type of plumbing emergency is the water leak.  This article will cover domestic (fresh water) cold or hot water leaks under pressure as opposed to drainage (brown or grey water) leaks that flow by gravity.  Although all leaks are critical from the standpoint of their potential for damage or from a conservationist perspective, one must evaluate and triage based on the criticalness of the problem.  I therefore categorize pressure leaks in two main categories, interior or exteriorleaks and will address them in order of importance.

Water Pressure Leaks (interior)

This is potentially one of the most damaging plumbing  emergency and must be handled swiftly to minimize property damage.  First, try to discover the source of the leak.  If the source of the leak is apparent, (such as a supply line leak to a lavatory fixture) your first action will be to turn the shutoff handle clockwise to eliminate the pressure.  If you can’t identify the source of the leak perhaps you can determine whether it is a hot or cold leak.  This information is important and can give you a back-up plan if the main cold water shut off is not functional and it is a hot water leak.  I will try to give you a template for action based on the type of leak.

Water Leak  (the source is known)

Example: leaking cold water supply line to kitchen faucet is leaking or washing machine supply hose

Action:  turn shutoff handle counter-clockwise to stop flow of water.  Open faucet to relieve and drain off pressure.  If this does not stem the flow of water in a minute or two, then you must take the next step which is to shut off the house cold or hot water supply.

Result: water will stop flowing, damage is minimized

Water Leak  (the source is not known)

Example: constant flow of hot or cold water piping inside of wall or from ceiling.

Action: your first action must be to shut off the house main cold water supply.  It is essential for the homeowner to know where his main water shut off valve is located and that it works.  Typically, the main water shut-off is at the front of the house directly in line with the water meter.

Result: both and cold and hot water will be de-pressurized and the threat will be reduced.

Alternate Action #1

You can shut off all the water in the house at utility provider’s water main, usually located at the front property line.  You will need a special tool called a “meter key” that is slotted to fit into the raised male end of the water service valve.  (You can purchase one at a plumbing supply, hardware store or ask your plumber)

Alternate Action #2

If you know that the leak is from a hot water pipe, you may alternatively shut off the incoming cold water valve to the water heater.  This action will, in effect shut down the flow of hot water to the home.  This has the advantage of allowing you to use the cold water in the house (to flush toilets, etc.) until a repair is made.

I hope that helps.  In a future post I will discuss what to do when you discover an exterior water leak under pressure, such a break in the main water service.  Until then, stay safe!


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