Everything To Know About How To Clear The Main Sewer Line Clog

Being a homeowner is an incredible responsibility that requires diligence and financial management. This is in addition to the routine cleaning, painting, and more routine repair and maintenance. While doing all this, at some point, you may handle the main sewer line unclogging.

A residential sewer line drains wastewater from a property into a larger pipe that sends it to a municipal sewage treatment plant. There are over 1.2 million kilometers of public sewer pipes and over 804,000 kilometers of private lateral sewer lines in the U.S.

For most homeowners, a sewer pipe is often out of sight and mind. But when it gets clogged, it can lead to a ton of problems. The longer you wait, the more likely the clog will deepen and create a major backup, one that could wreak havoc on your property and cause thousands of dollars worth of damage.

It may be necessary to hire a plumbing contractor to unclog the main sewer line. But the good news is that there are several ways you can try to resolve the issue yourself.

This guide walks you through the necessary steps to clear the main sewer pipe, signs to watch out for, when to seek professional help, and much more. Let us dive right in.

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Main Sewer Line Repair

From 12” Main Sewer Repair to Hydro-Jetting roots to cartridge replacements

Signs of Main Sewer Line Clog

You don’t have to wait until your property suffers damage to resolve a problem with your sewer line. This section discusses some of the signs of a main sewer line blockage so you can find and fix it on time.

  • Multiple Slow Household Drains: If you notice several drains moving slowly, it could signify a problem with the main sewer line. Multiple water fixtures (like toilets, bathtubs, sinks, and showers) might be affected. For example, you may notice that your toilet or sink overflows when you run the washing machine.
  • Gurgling Sounds: Is the water flowing in one secondary drain pipe causing gurgling in another drainpipe? If so, you might be facing a sewer line blockage. The gurgling sound originates from air escaping the drain.
  • Clogged Cleanout: The sewer cleanout is a sealed, upright pipe connecting to the main sewer pipe and is usually located in the basement or just outside your home. Water or sewage coming out of your sewer cleanout could indicate a clog farther along the sewer pipe.
  • Sewage Smells: Is a foul odor coming from your toilet, bathtub, shower, or sink? It is a primary indication of sewage backup often caused by a sewer line blockage.
  • Wet /Greener Patch in Your Yard: If you see an unexplained wet or greener patch in your yard during dry weather, it could be due to a partially clogged line.

Clogged Sewer Line Causes – Clogs Location

The usual culprits of sewer line blockage include:


One of the most common causes of household plumbing clogs is damage to a sewer line. If any of its parts are broken, it can cause sewage to back up through your toilets or drains, preventing waste from moving through the line properly. Such a situation calls for an immediate sewer line repair or replacement. Below are among the things that can cause damage to a sewer pipe:

  • Corrosion of an older pipe
  • Heavy traffic above the line
  • Soil shifting around the line
  • Construction near the pipe
  • Leaking joints due to broken seals

Sagging Sewer Pipe

A section of your main sewer line can sag due to shifting soil, age, or sinkhole. Paper and waste start collecting in the lower part, resulting in repeat clogs.


About 10% of Southern California’s households moved into their present home before 1990. That means over 197,000 families rely on old sewer lines for wastewater removal.

But older sewer lines constructed with clay or other porous materials and loose connections are prone to tree root infiltration. Roots can grow to incredible lengths in search of water sources. Upon infiltrating a sewer line, they expand further, causing more damage to the pipe and a total blockage.


Treating your toilet or sinks as trash cans will likely cause sewer pipe problems. Over time, the waste accumulates and obstructs the pipe. Debris can range from human hair, food waste, soap scum to wipes.

Grease and Fat

At Gallegos Plumbing, we highly advise against pouring oil, grease, and other fats down a drain pipe. These fats cool off, harden, and stick to the inner walls of your line, compromising the flow of waste.

How Do You Unclog a Main Sewer Line?

The methods to unclog a main sewer line primarily depend on the cause of the blockage. Below are few DIY options to consider:

#1. Ball Plunger

A ball plunger has a domed rubber surface at the top and a smaller base to resemble a mushroom. The design allows the plunger to fit the width of most toilets’ drain openings.

Below are steps to unblock your sewer line using a ball plunger:

  1. Choose a blocked toilet on the ground floor.
  2. Cover the overflow opening of your tub, shower drain, and sink with a washcloth, towel, or duct tape. This prevents the force created by the ball plunger from dissipating through the drain pipes.
  3. Fill the toilet bowl halfway with water. The water prevents air penetration, making it easier for the ball plunger to create a vacuum inside the drain opening of your toilet.
  4. Position the plunger so that it snugly fits the drain opening.
  5. Pump the ball plunger up and down to clear the clog. Concentrate more effort on the backward pull than on the downward push.

You will know the method is successful if the standing water in your toilet starts to drain. You can pour two or three gallons of boiling water into the toilet to help break down the clog.

#2. Baking Soda and Vinegar

Vinegar solution creates carbon dioxide and water, which bubbles through a blockage, loosening it up. The acidic property of baking soda helps dissolve grease and dirt. For this solution to work, take the steps below:

  1. Locate the sewer cleanout. Loosen the cap slowly and keep your distance. Contaminated debris or wastewater might spray out of the pipe, so wear protective glasses and rubber gloves.
  2. Allow the waste buildup to spill out of the cleanout.
  3. Mix vinegar (preferably white vinegar) and baking soda (one part each). Pour the fizzy mixture into the cleanout immediately.
  4. Pour hot water into the pipe after an hour.

#3. Chemical Cleaners

There are plenty of chemical pipe cleaners in grocery and hardware stores, ranging from acidic cleaners to oxidizing cleaners.

Each type of chemical cleaner is tailored to handle a particular clogging culprit. A caustic cleaner (often containing potash), for example, is best suited for grease, while an oxidizing cleaner (with bleach or nitrates) helps dissolve food and other particles. For invasive tree roots, use copper sulfate.

Because these products emit toxic fumes that can cause respiratory problems, always use them in a well-ventilated space. Be cautious not to mix chemical pipe cleaners or use two or more types on your sewer line; else, you increase the risk of a thermal reaction that could injure you and damage your sewer pipe. While enzyme-based cleaners are safer, they take longer to achieve expected results.

  1. Wear protective clothing. Chemical cleaners can harm your skin, eyes, and mucous membrane. So, make sure to wear a face mask, rubber gloves that extend beyond the wrist, and safety goggles.
  2. Read the manufacturer’s guidelines carefully to prevent unnecessary risks.
  3. Pour the cleaner directly into the sewer cleanout while avoiding spillages and splashes.
  4. Leave the chemical to work for about 30 minutes or longer for stubborn clogs.
  5. Run hot water down the cleanout pipe to wash away the chemical cleaner and move the dissolved blockage.
  6. Repeat the procedure until the clog clears.
  7. Dispose of the drain cleaner packaging carefully. Due to the hazardous nature of the content, avoid mixing the package with general waste.

#4. Snake Tool

A sewer snake is a long steel cable wrapped around a spool and equipped with a hand crank. The tool retails between $10 and $25 and is readily available in local hardware stores.

  1. Locate and open the cleanout plug. Some wastewater may leak out, so you will want to place a bucket below the cleanout plug.
  2. Once the spill out stops, insert and push the snake tool in the sewer line, rotating it clockwise.
  3. Continue pushing and rotating until the blockage clears out.
  4. You will want to hose down the plumbing snake before removing it from the sewer line. The water helps clean the auger and disintegrate any leftover blockage.

#5. Hydro-Jetting

Stubborn clogs require more force, and that is where a sewer jetter comes into the picture.

Also known as a water jetter or hydro-jetter, a sewer jetter is a powerful sewer cleaning machine that uses high-pressure water jets to clear blockages. It can be truck-mounted or mounted on a trailer pulled by a van or truck. Smaller equipment for lighter applications can be cart-mounted.

Drain and Sewer Hydro Jetting plumbing services comprises a motor/engine, pump, hose reel, hose of a particular length, and various nozzles, and the sewer jetter machines produce up to 4,000 PSI of water pressure and a flow rate ranging between 2 and 25 gallons per minute.

How to Clear the Main Sewer Line Clog

Here is how to unclog a main sewer line using a high-pressure hydro-jetter:

  1. Locate your sewer cleanout
  2. Put on rubber gloves and protective glasses to prevent your skin and eyes from coming into contact with debris or wastewater that might flow out of the pipe.
  3. Prepare the sewer jetter. Different methods have varying setup procedures, so be sure to follow the manufacturer’s instructions. Once the jet fills, turn on the pressure and wait until it reaches the recommended level.
  4. Lower the nozzle down the cleanout pipe, far enough to prevent wastewater from splashing on you.
  5. Turn on the water and continue feeding the hose down the sewer line. Expect some backsplash when the water from the nozzle hits a clog near the cleanout. You know you have successfully unclogged your sewer pipe when the backsplash stops and wastewater starts rushing down the line.
  6. Turn off the hydro-jetter before pulling the hose out of the line.
  7. You will need to wash the hose but first detach it from the main machine. Wipe down the hose using a cloth dipped into a warm water-soap solution.

The Problem with DIY Clearing a Main Sewer Line Clog

You can save an incredible amount of money by fixing some issues around your home. Still, DIY projects offer great opportunities to learn new skills, so you do not have to call a professional to handle common household problems. And with easy access to the internet, it is now much easier to grasp a new skill through articles and YouTube tutorials.

However, there are several reasons why you should avoid a DIY sewer line repair. You may not be conversant with utility line locations, soil conditions, and the best methods to address different sewer line scenarios. Secondly, the subtle nature of sewer line damage demands the right equipment and proper materials that are often not readily available to the average homeowner.

So much can go wrong with DIY sewer pipe repair. A minor problem can escalate into extensive damages. For example, trying to fix a leak in your yard could cause a spill into your neighbor’s compound or a sewer backup inside your home. In Gallegos Plumbing’s experience, it can cost thousands of dollars to fix incorrect work.

Do not overlook the possibility of violating local building and public work codes. Code violation could set you up for liabilities and an expensive re-do of your project.

Consider also the health and safety risks associated with sewer lines. Harmful bacterias can put your body at risk of infections. You may also hit a natural gas line which is not only bad for your respiratory system but could also cause fire or explosion damage to your or your neighbor’s property.

By hiring a professional plumbing contractor, you get the confidence that your sewer line problem will be diagnosed and fixed professionally and in compliance with industry standards and local regulations.

Common Sewer Line Repairs


In cases of severe damage or complete collapse, sewer line repairs will involve excavation. It involves digging up the old system and installing a replacement. Excavation can be done manually or using more advanced equipment such as excavators or backhoes, depending on the project’s scope.

Trenchless Sewer Repair Method

Trenchless sewer repair is among our core specializations at Gallegos Plumbing. Unlike excavation, trenchless options are faster and less destructive, which means more time and money savings.There are two common types of trenchless sewer repair: Pipe Bursting and Pipe Relining.Pipe bursting/pipe pulling involves inserting and pulling high-density polyethylene pipe through an old damaged sewer line. This technique requires digging holes on both ends of the lateral sewer pipe. The new pipe has a unique head that bursts open and fractures the damaged pipe without removing it.

Pipe lining or cured-in-place pipe (CIPP) involves installing an epoxy liner into a damaged sewer pipe. It is essentially building a new pipe within an existing sewer line. It requires one point of entry through which our technicians insert a strong epoxy to line the walls of your old pipe. The epoxy hardens after 3-4 hours.

How Much Does It Cost for a Main Sewer Line Replacement?

According to a report by Angi (formerly Angie’s List), the average cost of replacing a sewer line ranges between $50 and $125 per foot. The total cost typically runs between $3,000 and $25,000. The type of replacement pipe also factors into the expenses. You can choose between cast iron and plastic pipes.

Plastic sewer pipes have long been a standard for the industry. They are cheaper and can be replaced in parts. However, they are more prone to damage from heavy or regular traffic, shifting soil, or freezing temperatures.

Cast iron is a durable piping material. It resists pressure well, but it’s also expensive (costing at least twice as much as plastic pipes).

It is vital to understand that you will likely pay for the sewer line replacement out of pocket.

Ninety-five percent of homeowners have homeowners insurance. Most expect their policy to cover sewer pipe repair/replacement, but this is not always the case. Your insurance will likely cover damage caused by a sudden occurrence (like an earthquake). Typically, homeowners insurance does not cover sewer pipe damage originating from regular wear and tear.

How to Keep the Main Sewer Line Unclogged – Sewer Line Preventive Maintenance

How To Clear A Main Sewer Line Clog

Preventive maintenance keeps your sewer line working smoothly, prevents potential disaster, minimizes calls for sewer line repairs, and prolongs the line’s lifespan. Get started with the following tips:

  • Avoid pouring fatty or oily substances into your sinks. You can install a grease receptor under your kitchen sink.
  • Do not dispose of food waste in your kitchen sink,including corn husks, starchy food remains, banana leaves, eggs shells, coffee grounds, and onion peels
  • Ensure only human waste and one-ply toilet paper is flushed down your toilet. Female hygiene products, paper towels, adult and toddler wipes, and extra-thick toilet paper can clog your sewer pipe.
  • Flush your plumbing system at least monthly. Fill all water holding devices in your home, including sinks, bathtubs, and washing machines, with cold water and then drain them simultaneously.
  • If you live in a low area, set your toilets to the highest flush volume.
  • Schedule regular inspections. Gallegos Plumbing technicians are trained to conduct periodic sewer camera inspections. The process involves inserting a camera into the cleanout pipe and directing it along the sewer pipe. Video inspections help pinpoint the exact problem and its location in the sewer line, preventing expensive trenching and saving time. Regular video inspections can help detect and fix sewer problems early, saving you from costly repairs and replacements.