Should You Turn Off Taps When Dishwasher Not In Use?

Any appliance which uses water at mains pressure is under pressure and as such has the potential to leak. Most dishwashers are connected to the cold water supply via a feeder pipe connected to a tapped main supply. So, yes, you should turn off the taps when the dishwasher is not in use.

It is important to turn off the water supply tap to your dishwasher when it’s not in use

Why Is It Important To Turn Off The Taps When The Dishwasher Isn’t In Use?

It’s important to turn the taps off which supply water to your dishwasher when it’s not in use for several reasons. Which are;

  1. Pipe Failure
    Over time water pipes become worn. Worn pipes have the potential to leak.
  2. Joint Failure
    The joints and connections where pipes meet or join the machine have the potential to leak.
  3. Valve Failure
    The main inlet valve on the dishwasher should close when the machine is not in operation. If it fails to close, there is the potential for your kitchen to become flooded.

Hydraulic Shock

Whenever your dishwasher shuts off the water, it causes a condition commonly known as a water hammer. Which is actually hydraulic shock, or to put it simply it’s like a mini tidal wave running through the internal pipes of your dishwasher.

Over time this constant shock wave effect can cause pipes to move and joints and connections to wear out. All of which can cause your dishwasher to develop a leak. If the dishwasher is connected to the main water supply, there is nothing to prevent it from flooding your home.

Manufacturers Recommendations

All of the dishwasher manufacturers recommend turning the water off from the mains when the machine is not in use. This is especially important if you intend to leave your home empty overnight. They also recommend regular check ups of the pipes and connections for any signs of moisture etc.

If you do spot a leak or any moisture, contact the manufacturer if the machine is still under warranty, or an independent engineer if not.


Another good reason to ensure you turn the water supply off from your dishwasher when you’re not using it, is the terms and conditions on your household insurance policy. Many insurance companies will not pay out if your home is flooded by a dishwasher.

They term this as negligence because dishwasher manufacturers recommend turning the appliance off from the water supply when not in use.

Always remember to turn the water supply back on before using your dishwasher to prevent any damage to the machine.

How To Find The Dishwasher’s Water Supply Shut Off Point

Your dishwasher will have an inlet hose usually situated at the top of the machine at the rear. Follow this pipe away from the machine and you will find it is attached to a tap of some sort. Turn this tap to the off position and your machine cannot cause your home to flood.

Frequently Asked Questions

How do I turn off my dishwasher tap?

Trace the inlet hose back from the machine to the tap on the pipe. Turn the tap clockwise to ensure it is shut off completely.

Where is my dishwasher shut-off valve?

The pipe that feeds your dishwasher is usually located  under the sink next to the dishwasher. It should have a tap or hand shut off valve on the pipe.

How do I turn off the water to my dishwasher in the UK?

To turn the water to the dishwasher off, you’ll need to trace the inlet hose backwards from the machine (usually under the sink). The hose should have a washing machine valve attached to it. Turn the valve so that it points across the pipe instead of alongside it. This turns the water off to the dishwasher in the UK.

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