How Do I Unclog My Main Sewer Line?

A clogged main sewer line is one of the most serious plumbing problems a homeowner can face. Unlike a single drain clog, a blockage in the main line affects your entire plumbing system and can quickly lead to backups in multiple areas of your home.

If you suspect your main sewer line is clogged, here’s what you need to know, what steps you can take, and when it’s time to call a professional.

Signs Your Main Sewer Line Is Clogged

Before we dive into how to unclog it, let’s make sure you’re dealing with a main line issue. Common warning signs include:

• Multiple drains backing up at once (toilets, tubs, sinks)

• Gurgling sounds from drains or toilets

• Water backs up in the shower when you flush

• Sewage smells in your home or yard

• Slow drains throughout the house

If you’re experiencing two or more of these symptoms, the issue is likely in your main sewer line, not just a single pipe.

Steps to Unclog Your Main Sewer Line

Here are a few methods you can try before calling in a professional. Keep in mind, some of these require tools and experience.

1. Shut Off the Water

Before anything else, stop running water inside the house. This will prevent additional backups and flooding while you work on the issue.

2. Check the Sewer Cleanout

Locate the outdoor sewer cleanout pipe (usually near your home or along your property line). Remove the cap slowly, if water starts spilling out, that’s confirmation of a main line clog.

3. Use a Plumbing Snake (Auger)

If you have a long drain snake, insert it into the cleanout pipe to try and break up or remove the clog. If it hits resistance and then breaks through, that’s a good sign, but the problem may return if it’s only a temporary fix.

4. Try a Hydro Jet (If Available)

Hydro jetting uses high-pressure water to clear out sludge, grease, and debris. This method is more effective but requires special equipment and training. Best left to professionals.

5. Avoid Chemical Drain Cleaners

They may work for minor clogs in sink drains, but are not recommended for sewer lines. They can corrode your pipes or create bigger blockages down the line.

When to Call a Professional Plumber

If none of the above steps work, or if you don’t feel comfortable trying them, it’s time to call a licensed plumber. A clogged main line can lead to severe water damage and even health hazards if not handled quickly and properly.

Professional plumbers use tools like:

• Video camera inspections to locate the exact blockage

• Commercial-grade augers or hydro jetters for deep cleaning

• Trenchless repair techniques if your pipes are damaged or collapsed

Preventing Future Main Line Clogs

After your main sewer line is cleared, it’s smart to take steps to prevent another backup:

• Don’t flush wipes, feminine products, or paper towels, even if they say “flushable”

• Keep grease out of the kitchen sink

• Schedule annual drain maintenance or inspection

• Trim roots near your sewer line if tree intrusion was the cause

Unclogging a main sewer line can be messy and dangerous without the right tools or experience. If you're dealing with sewage backups or slow drains throughout your home, don’t wait, it could get worse fast.

Call Vertical Plumbing at (480) 577-8720