How to Unclog a Washing Machine Drain Easily

Clogged Washer Drain Backing Up?

A washing machine drains water into the drainpipe through the drain hose at the back of the washer, after every wash cycle. This water flows out of the washing machine drainpipe and into the main house drainpipe and finally out into the city sewer line or septic tank.

If you notice water pooling around the base of your washing machine, you most likely have a clog in the drain, the drain hose is pushed too deep inside the standpipe or the standpipe is of a smaller size, restricting the flow of water. This causes the washing machine drain to overflow.


A clogged or slow draining washing machine is caused by soap residue, lint, hair, grease, oils and other debris that accumulate in the drainpipe restricting the flow of water. Whenever you notice water pooling around the bottom of your washing machine, a clogged drain is usually the first culprit.

To unclog a washing machine drain, remove the drain hose from the drainpipe and snake the drain with a drain auger. Alternatively, you can use a boiling water, baking soda and vinegar combination to break down the clog. If you have to use a commercial product, go with an enzyme-based drain cleaner.

A clogged and backing up washer is different from a washer that won’t drain. A washer that won’t drain is caused by a faulty drain pump, clogged drain hose, malfunctioned lid switch among other factors.

With a washer that wont drain, the tub will be full of water after a wash cycle and your clothes will be dripping wet. To read more about a washing machine that won’t drain check out this post.

Determining the Depth of Washer Drain Clog

When you have a clogged and backing up washer, it helps to first determine the depth/position of the clog so that you can decide on the best way to unclog it. Doing this is actually easier than you may think.

  • Start by pulling your washer forward. You want to be in a position where you can access the washer’s control and also see the drain.
  • Fill the washer drum with water and set the dial to drain.
  • As soon as the washer starts draining, notice how long it takes for water to start overflowing from the drain.
  • Turn the washer off immediately the drain starts to overflow.

Just to let you understand how a washing machine drain looks like, the washing machine drain hose drains into a vertical pipe called a standpipe. At the bottom of the standing the pipe curves into a U-shape.

Image courtesy: RemoveandReplace

The U-shape part of the drain is called a P-trap or drain trap. Every fixture in your house with a drain has a P-trap. If you look under your kitchen/bathroom sink you will see one.

The P-trap traps potential drain clogs preventing them from clogging the drainpipe farther away where unclogging it would be way harder. If you washing machine is clogged or draining slowly, most of the time the clog will be located there.

The second function of the P-trap is to hold a little amount of water at all times, which creates a barrier preventing sewer gases from coming up through the drain. Anytime you have a sewer gas smell coming from your washing machine drain, the water will have evaporated, breaking the barrier.

Pouring a small amount of water down the drain is usually enough to fix the problem. This will replace the evaporated water thereby reintroducing back the barrier.

In the above test, if it takes about 30 seconds to 1 minute before water starts overflowing out of the washing machine drain, the clog is located in the P-trap. If it takes more than a minute then the clog is located somewhere in the main house drainpipe and will be harder to unclog.

How to Unclog a Washing Machine

There are several ways to unclog a washing machine. Some are easy and quicker than others, but that will depend on the severity of the clog.

The good thing about washing machine clogs is that they are not as bad as those of a toilet or kitchen sink. Very few solids are able to go through the drain and therefore unclogging it is relatively easier.

If I had a clogged washing machine, this is how I would unclog it:

1. Inspect the Drain Hose

Several things can go wrong with the washing machine drain hose. Before proceeding further with the fix, you should turn off or unplug the washing machine from the power outlet.

For you washing machine to drain properly, the drain hose needs to be smaller in diameter compared to the standpipe. Ideally, there should be a ½ inch gap between the drain hose and the standpipe.

The smaller gap between the drain hose and standpipe allows air inside the drain for faster draining. This is however hardly the issue since it if were, you would have noticed it the very first time you used the washer.

What can however happen is that debris can accumulate all around the drain hose inside the standpipe effectively blocking the gap between the hose and the standpipe. As a result, the washing machine will start to drain slowly leading to overflowing and pooling of water at the bottom of the washer.

Another thing that can happen with the drain hose is that if you stick it way to deep inside the standpipe, water will not drain out as fast as it should. This is because there will be not enough air circulation.

For proper drainage, the drain hose should be inserted 6-7 inches inside the standpipe. putting the drain hose to dip can even siphon water out of the tub, causing the washing machine to drain when filling.

Pull out the drain hose from the standpipe and inspect its condition. If it is strapped to the drainpipe cut the straps with a knife.

You will most likely see a gross gunk on the drain hose part inserted in the standpipe. Cleaning the drain hose might be enough to fix the problem but most of the time you will need to unclog/clean the standpipe and P-trap as well.

2. Use Baking Soda and Vinegar

Baking soda is an alkaline substance, scientifically known as sodium bicarbonate. Vinegar on the other hand is a weak acid formed by mixing acetic acid and water.

When you mix baking soda and vinegar, a reaction occurs producing carbon dioxide gas and water. It is this reaction that breaks downs clogs into smaller pieces that are easy to flow down the drainpipe.

Here is how to unclog a washing machine using baking soda and vinegar:

  • Start by running hot water down the drain. Remove the drain hose and insert a funnel inside the standpipe. Slowly pour about a gallon of hot water. The water hot is very effective in dissolving and breaking down soap buildup and other gunk inside the drainpipe and can actually unclog the washer on its own.
  • Pour 1 cup of baking soda down the drain followed slowly by another cup of vinegar.
  • Give the baking soda and vinegar solution 10-15 minutes to work out its magic.
  • Insert the funnel in the standpipe and blast hot water through the drain. While baking soda and vinegar will have done most of the work, the boiling water will break down the clog even more and flush it down the drain as well.

Apart from unclogging drains, baking soda and vinegar are also very effective in drain odor elimination. You should actually make it a point of pouring baking soda and vinegar down your drains at least once a fortnight to prevent clogs and keep drain smells at bay.

3. Snake the Washer Drain

Drain snakes, also known as augers are very effective in unclogging drains. Before you using an auger to attempt unclogging your washing machine drain, there is one trick you can use to dislodge the clog.

  • Remove the drain hose from the standpipe and go grab the garden hose
  • Stick the garden hose inside the standpipe and use try and dislodge the clog. It works even better with the water running out of the hose as the water carries away with it the smaller debris that have been broken down.
  • Blast hot water down the drain to wash down the debris and confirm if you were successful.

If the garden hose doesn’t do it, you will need to upgrade to a proper drain auger. A drain auger contains a flexible cable rolled on a drum, and has a spring-like head with a hook, and a cranking handle.


Here is how to unclog a washing machine with a drain snake:

  • Remove the drain hose from the standpipe.
  • Start feeding the cable down the standpipe until you encounter resistance.
  • Use the clamp on the drum to lock the cable.
  • Start cranking the handle slowly, to try and penetrate the clog.
  • When the handle feels and starts moving freely, release more cable from the drum and keep pushing it down the drain until you are confident that the clog has been removed.
  • Pull out and clean the cable.

And basically, that is how to unclog a washing machine drain. If unfortunately you are unable to unclog it, go ahead and call in a professional plumber.

Plumbers have more experience and even better tools to deal with clogs. Some drain clogs can only be removed by plumbers.

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