How To Stop Your Washing Machine Drain From Overflowing

If your washing machine drain overflows, the cause could range from a simple clogged drainpipe to a more serious main sewer line blockage. Acting quickly can help prevent water damage to your home. This guide will help you identify the issue, walk you through a do-it-yourself (DIY) fix, and explain when it’s best to call a professional.

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How a Washing Machine Drains

At the end of a cycle, your washing machine removes water from its tub using a pump that forces water into a washing machine drain hose. This hose curves up and out of the machine to meet the standpipe, which is typically located near your hot and cold water supply valves. If your washer and its parts work as they should, water moves through the hose and into the standpipe, where it’s eventually carried to your home’s main sewage line.

When any part of the process malfunctions, the washing machine’s drainage system may overflow, requiring swift action to identify and fix the issue.

In the video below, Ask This Old House plumbing and heating expert Richard Trethewey explains how to install an automatic shutoff valve for your washing machine supply hoses.

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How To Diagnose an Issue With Your Drain

First, you’ll need to confirm that your washer’s drain line is the issue. Some advanced washing machines have signal errors to identify the cause of a leak, but you’ll need to run your own diagnostic test with most models.

Start by running your washer through a drain cycle. Observe the washing machine as it pumps water into the hoses and up into the standpipe. If you see water back up and out of the standpipe, your washer’s drain is most likely the issue.

The amount of time it takes for the standpipe to fill up and overflow helps you diagnose where the clog is located. Here’s what each time frame might mean:

• A few seconds: If the pipe fills up and overflows within seconds, the clog is most likely located near the standpipe’s surface or in a washing machine hose. If the clog is small, you may be able to clear it with a hand-operated snake.
• Thirty seconds to one minute: If the stoppage doesn’t cause the water to surface for 30 seconds or more, the clog may be deeper in the drainpipe system. This may require a long drain snake to reach deep into the pipe and free the clog. If you can’t reach the clog with your snake, contact a plumber to assess the proper course of action.
• More than one minute: Water that takes more than a minute to overflow after entering the drainage pipe may indicate a more severe blockage deeper within the plumbing system. Contact a licensed plumber to inspect your home’s sewage lines and identify the issue.

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How To Operate a Drain Snake

You can clear many soft-debris clogs that reside in a washing machine hose, standpipe, or plumbing system with a drain auger, also known as a drain snake. If you don’t have a drain snake, you can usually rent one from your local hardware store. Some electrically powered, hand-operated drain snakes are less likely to damage your plumbing. To operate a snake, follow these steps:

1. Push the tip of the cable into the drain opening and turn the handle on the drum to release it into the pipe. You may need to loosen a thumbscrew on the drum to allow the cable to unspool.
2. Keep pushing the head of the snake deeper into the pipe until you feel resistance.
3. Tighten the thumbscrew, then rotate the snake clockwise or counterclockwise until you feel the clog break free.
4. Loosen the thumbscrew once again, then pull the snake out of the drain.
5. Repeat a drain cycle to ensure the pipe is clear and can drain.

If the drain snake meets resistance but these steps don’t work, the clog may be made of material that’s too hard for the tip of the cable to snag, such as a tree root. In this case, you’ll need to call a plumber. Another culprit could be your city’s sewage system being improperly maintained, resulting in your main line backing up.

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How To Prevent Your Drain From Overflowing

To reduce the likelihood of a washing machine drain overflow, clean and inspect your washer and its parts regularly.

• Use a garment or lint bag: Small clothing fibers and debris can accumulate in a washing machine drain over time. Using a garment bag for delicate items or a lint bag can help prevent excess lint buildup inside the drainpipes.
• Check and clean the lint trap: Some washing machines have a built-in lint trap or filter that can become clogged. If your machine has one, inspect and clean it regularly to maintain proper water flow.
• Maintain proper hose placement: Ensure the discharge hose is inserted into the drainpipe with at least half an inch of space around it. This gap helps prevent siphoning issues and promotes smooth drainage.
• Use the right laundry detergent: High-efficiency (HE) washers require low-sudsing detergent. Using too much or the wrong kind of detergent for your washing machine can lead to soap residue buildup, which can contribute to blockages.
• Clean the hoses and drainpipe: Over time, detergent residue, lint, and mineral deposits can accumulate inside hoses and the drainpipe. Periodically flushing your washer’s hoses and drainpipe with hot water or a mild cleaning solution can help keep them clear.

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Repairing or Replacing Your Washing Machine

Like all major systems and appliances, your washing machine is likely to endure normal wear and tear over time. So if drainage issues persist you may need to replace the machine and install a new washer. To cover repair costs due to your washing machine or another appliance breaking down from normal use, we recommend that homeowners consider a home warranty.

Typically, home warranty plans cost $54–$61 per month. Whenever a covered system or appliance breaks down due to normal wear and tear, homeowners with a home warranty plan only have to pay a service fee—usually in the range of $65–$125—to have the item repaired or replaced. This can save you a lot of money in the long run, particularly for owners of older homes or expensive appliances like a washing machine.

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Our Conclusion

When your washing machine drain overflows, acting fast can help minimize water damage, prevent mold growth, and avoid costly plumbing repairs. Start by diagnosing the issue—whether it’s a simple clog, improper hose placement, or a more serious plumbing problem. Attempting a DIY fix can offer a cost-effective solution, but if you’re unable to resolve the issue or suspect a main sewer line blockage, it’s best to call a professional.

Hiring a licensed plumber ensures the problem is properly diagnosed and fixed, reducing the risk of recurring issues. Before choosing a service provider, get multiple quotes, check reviews, and ask about warranties to ensure you’re getting the best value for your repair. Taking these steps can save you time, money, and future headaches.

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FAQs About Fixing Washing Machine Drain Overflows

Why does my washing machine keep draining?

If your washing machine drains while filling, check that the washer’s drain hose isn’t placed too far into the standpipe, as there needs to be an air gap to prevent premature draining. Additionally, ensure that the bend in your drain hose is above the height of the washing machine. Once the hose is in the proper position, use zip ties to secure it in place.

What causes a washing machine drain to overflow?

The most common reason for overflowing is a blockage in the drain hose or standpipe. Kinked hoses and wrong-sized pipes can also cause overflows.

Can I put Drano down my washing machine drain?

Yes, you can use Drano or any drain cleaner to unclog your washing machine drain. However, don’t put the Drano in the washing machine itself, and make sure you run the washer without a load of laundry before normal use. Learn how to maintain a washer and dryer effectively with our guide.