Does a Washing Machine Need a Drain Pipe?

When the plumbing of your washing machine clogs up and you’ve some urgent laundry to do, you may be tempted to operate the washer without connecting it to the drain pipe. But will the machine work, and is it safe to do so?

A washing machine needs a drain pipe to hold water in its washtub and operate properly. Without a drain hose connecting the washer’s water outlet to the drain pipe, water will keep flowing out, and the washtub will not fill up. However, there are some workarounds if no drain pipe is available.

Does A Washing Machine Need A Drain Pipe?

In the rest of this article, I’ll explain in more detail why washing machines need drain pipes and how the pipes work and are connected to the washer. I’ll also share with you some ways to operate a washing machine without a drain pipe and how some washer models are designed to work without drain pipes.

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Why a Washing Machine Needs a Drain Pipe

Operating a washing machine without a drain pipe can leave a big mess for you to clean up; your clothes may not even get washed.

In the traditional washing machine setup, the drain hose and pipe serve two vital functions:

  • Keep the washtub filled with water for washing and rinsing.
  • Drain the dirty water.

Let’s take a closer look at these functions.

The Drain Pipe Helps Hold Water in the Washtub

The washing machine’s drain hose runs from the bottom of the tub to the top of the washer (or higher) before looping down into the drain pipe.

Hydrostatic pressure comes into play, ensuring water remains at the same level in the washtub and the drain hose.

When the washing machine’s motor pumps water into the tub, the water in the drain hose rises in tandem but doesn’t flow out.

Hydrostatic pressure is the pressure exerted by a fluid under the force of gravity.

With hydrostatic pressure, the washtub and the drain hose work like two “communicating vessels,” a scientific concept that explains why a fluid poured into a network of connected vessels settles at the same level in all of them.

Dirty Water Is Pumped Out Through the Drain Pipe

So far, so good. But how is the dirty water discharged from the tub? That’s the most interesting part.

The motor operates in the reverse direction to pump the dirty water out of the tub, forcing all of it up the drain hose and into the drain pipe.

Will a Washing Machine Work Without a Drain Pipe?

If there’s no drain pipe installed near the washing machine, you may wonder if you could place the free end of the drain hose into the main drain line near the floor.

You probably could, but it won’t work because the washtub will not fill up as the water will continuously flow out through the drain hose.

The tub and the hose are not communicating vessels in this scenario.

However, you can work around the problem.

For instance, you could place the free end of the drain hose in a sink or run the drain hose over a tall chair and drop it into a bathtub or a large container.

These workarounds are not permanent solutions and come with an element of risk.

The sink could overflow, or the hose could drop to the floor if it’s not properly clamped.

In both cases, you’ll be left with a soapy, slippery mess on the floor that could be a safety hazard.

You’ll likely get a similar outcome if you try to run a washing machine without a drain hose.

READ: Washing Machine Flow Restrictor

How To Connect a Washing Machine to a Drain Pipe

Now that we know washing machines need drain pipes, let’s see how we can ensure the drain-pipe setup works correctly.

In most homes, the drain pipe is a vertical standpipe about 3 to 4 ft (0.9-1.2 m) tall and open at the top.

All you need to do is put the free end of the drain hose into the standpipe opening.

Don’t make it fit tightly, and make sure there’s an air gap around the hose.

Water does not flow well in a closed pipe; it flows better with air behind it.

If your washing machine does not have a drain hose, perhaps it was damaged or lost during a recent move, you should consider getting a replacement.

I recommend MyLifeUNIT Washing Machine Drain Hose (available on This 6 ft (1.8 m) drain hose comes with two stainless steel clamps and an extension adapter for effortless installation.

The Caveat: Some Washing Machines Work Differently

All washing machines don’t work the same way.

Although traditional washing machines in most U.S. homes generally work the way I’ve described above, some operate differently.

Some washing machines have, hidden within their frames, a hose connecting the washtub to the top of the washer.

On the outside, you’ll only see a water outlet near the top to connect the drain hose.

For this type of washing machine, you don’t need to run the drain hose higher (as it’s already done within the machine’s frame).

You can connect the hose directly to the drain line, bypassing the standpipe.

A few new washing machine models depend on gravity to drain the dirty water and fill the washtub, and their water outlets are below the tub.

Again, you don’t need a drain pipe as the drain hose is at floor level or concealed within the floor.

Final Thoughts

You may be able to operate your washing machine without a drain pipe in some situations, but it’s not a recommended practice.

It’s not only unsafe but also a tad inconvenient.

You lose the convenience of an automatic washing machine as some manual effort is involved, and you must constantly watch the washer to ensure there’s no water spillage.

So if your laundry room has no drain pipe, consider calling in the plumbers to install one and make life a little easier for yourself.

Cheers, tools owners!

Hi there! My name is Jack and I write for ToolsOwner. I have a passion for everything related to tools and DIY projects around the house. You often find me in my workshop working on new projects.