What to Do About a Clogged Sewer Line

Feeling out of sorts because you have a clogged sewer line? A plumbing issue caused by a clogged sewer line in the basement, cellar, or outside can be expensive and frustrating to deal with, but it doesn’t have to spell disaster.

clogged sewer lines

If you think that your sewer is clogged, follow these guidelines to learn how to spot an issue, how to fix it, and when to call in a pro.


What Causes a Clogged Sewer Line?

A clogged sewer line can stem from:

  • Tree roots. Tree roots cause the majority of sewer line clogs, particularly in older houses. Drawn to the warmth and moisture offered by sewer lines, tree roots enter the pipes through any tiny cracks or loose joints they can find. Feeding on the plentiful nutrients they find there, the roots grow and create blockages in the sewer line. Over time, the small sewer line molehill created by tree roots becomes a big mountain of debris.
  • Fats, oil, and grease. Known in the plumbing community as FOG, fats, oil, and grease can sometimes lead to a clogged sewer line. When hot, these substances seem liquid, so many people pour them down the drain without another thought; but as soon as they cool off, they congeal, trapping debris and causing blockages. 
  • Foreign objects. Tampons, pads, diapers, paper towels, facial tissues, baby wipes, and even extra-thick toilet paper can get stuck in your pipes, collect debris, and cause a sewer line stoppage. 
  • Old sewer lines and plumbing issues. If you live in an older home and have not replaced your piping system, your sewer pipes will inevitably develop cracks and breaks that end up in total piping system collapse. Even if your home has a newer piping system, if the plumbing connections are poorly made, it may cause a sewer line clog.

How Do I Know if I Have a Main Sewer Line Clog?

Tell-tale signs that your sewer line is clogged include:

  • Gurgling sounds. Any gurgling, gargling, and glugging sounds coming from your toilet means you may have a sewer line clog.
  • Malodorous smells. If your drains aren’t smelling normal, it could indicate that you have a clogged sewer line.
  • Slow-running drains. Multiple slow-running drains and low water pressure in your home also suggest a sewer line issue.
  • Water in strange places. If you have a fountain of water pouring from your shower head when using the washing machine or water comes up in the tub when you flush the toilet, heed our fount of wisdom: it may mean your sewer line is clogged.
  • Sewage in your sink. The grossest sign of all, sewage coming back up through the drains into your sink, shower, or tub is a surefire sign that your sewer line has a problem.

However, just a single slow-flushing toilet or slow-flowing drain does not necessarily indicate a blocked sewer line. You will usually have problems with all the drains in your home at the same time, especially the toilets. When it comes to a clogged sewer line, the porcelain throne is king. Toilets have the most direct route to the sewer and the biggest drain line. If your toilets are causing your home’s other drains to overflow when they are flushed, or if your toilets overflow when you use the washing machine or dishwasher, it’s highly likely that you have a sewer line problem.

How Do I Diagnose a Clogged Sewer Line?

To pinpoint the exact cause of your clogged sewer, you may need to explore the nitty-gritty depths of your sewer line through a camera inspection. Hypothesis-based dig points are a thing of the past; these days, a sewer video inspection professional will come to your house to run a video line through your waste pipes and locate the source of the blockage. 

Think of the camera inspection as analogous to an endoscopy: the camera travels through the pipes and records any issues in real-time detail. The camera unit will transmit the blockage point location through a locating device. This point indicates where you should dig the sewer trench.

Once you have diagnosed the clogged sewer line, the next step is figuring out how to unclog a sewer line.

How Do I Unclog a Sewer Line?

Since a sewer line clog means your home may become unlivable due to unusable toilets and sinks. You’ll need to perform a sewer line cleanout immediately after diagnosing the problem. Doing so will allow you and your family to return to a grime-free home with working pipes. 

First, shut off the water to release sewer line pressure. If you have a main sewer line clog, you can help release some of this pressure by turning off your water at its main supply source or at street level. Then, scout around and see if you can locate the sewer cleanout line, usually a small white pipe around three to four inches in diameter and sealed with a screw-on cap. Unscrewing the cap can help unscrew your line since it should release any built-up pressure and encourage any backed-up water to drain. 

After you release the pressure, the following can help unclog your sewer line:

  • Chemical cleaner. Though effective, using chemicals to unclog a sewer line can be a safety hazard, so make sure to wear proper safety attire and follow all Environmental Protection Agency guidelines for chemical usage. Before using chemicals, make sure the sewer line doesn’t have any breaks. If your sewer line is clogged due to tree roots, most plumbers recommend using a copper sulfate-based chemical cleaner, which will help kill tree roots within two weeks of application. If it appears to be a toilet paper jam, you can try using a bleach-based chemical cleaner, which can help dissolve the blockage. Although you should follow the directions of whatever chemical cleaner you choose, generally, you will pour the chemicals down the sewer pipe and leave it for at least 15 minutes. Afterward, be sure to flush out the pipe using hot water. 
  • Non-chemical cleaner. If you want more earth-friendly home remedies for a clogged sewer line, combine one part baking soda with one part lemon juice or vinegar. Pour the mixture down the drain and let it sit for at least an hour before running hot tap water down the sewer line. 
  • Plumbing auger. You can try snaking your sewer line using a plumbing auger, which may allow you to break up the clog or remove the debris enough to remedy the problem. However, it’s a general rule of thumb that by the time you notice a sewer line clog, it’s too late to fix yourself with a standard drain auger. More powerful, professional tools are usually required. Some professional augers are power-assisted or even truck-mounted, meaning that they can provide extremely powerful mechanical drain cleaning. A professional-grade augur is usually fed into the sewer line in sections until your plumber can reach and break apart the clog.
  • High-pressure water jet. Water jet sewer cleaning uses a high-pressure hose hooked up to a water pressurizer. Water surges out of a specialized nozzle head and into your sewer line, breaking up debris and thus unclogging the pipe. A strong water jet can pulverize built-up debris and thoroughly clean out your sewer line. Earth- and budget-friendly, and generally a safer option, regular water jetting can even allow you to keep your sewer lines open longer by increasing their efficiency and effectiveness over time. Just make sure that there are no breaks in your sewer line before you use this method.

Sometimes a plumber will even recommend using three methods: chemicals to break up root issues, an auger to further dismantle debris, and finally, a high-pressure water jet to complete the job. 

How Much Should I Expect to Pay for a Sewer Line Cleanout?

Unfortunately, a blocked sewer line can also block your financial goals if you’re not prepared. Altogether, clogged sewer line cost is often in the thousands of dollars.

  • A sewer camera inspection costs $700 on average, although it can range from $250 to $4,000 depending on your location and specific home requirements. 

  • On average, it costs between $175 and $1,000 to clean out a sewer line. Snaking is on the lower end of the spectrum, ranging from $150 to $500. High-pressure water jetting generally costs between $250 and $800. 

Does a Home Warranty Plan Cover a Sewer Line Cleanout?

Signing up for a home warranty plan will give you peace of mind that your household is protected. A home warranty from American Home Shield® offers coverage for your home’s key systems and appliances, including plumbing warranty coverage. We will clear mainline drain and sewer stoppages through an accessible access cleanout up to 100 feet from an access point. 
AHS also offers Appliance Warranties and protection plans. 

Spotting, diagnosing, and clearing a clogged drain or sewer line shouldn’t be rocket science. With these tips on repairing a sewer line clog, your household will be back up and running again in no time. Check out our plans and pricing information to see which home warranty plan works best for you before a clogged sewer becomes a down-in-the-dumps day.


AHS assumes no responsibility, and specifically disclaims all liability, for your use of any and all information contained herein.

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