Hydro Jetting
High-pressure water jetting to thoroughly clean the inside of your main line — not just punch through the clog.
LEARN MOREMain Line Stoppage & Sewer Backup
Clearing severe main sewer line blockages for South Bay homes.
What Is a Main Line Stoppage?
Your home's main sewer line is the single pipe that carries all wastewater — from every toilet, sink, shower, and drain — out to the city sewer or septic system. When it gets blocked, nothing can drain.
Unlike an individual clog (which only affects one fixture), a main line stoppage affects the entire house. Water backs up in multiple places at once, often starting at the lowest fixtures — floor drains, tubs, and toilets on the ground floor.
Call (310) 493-034830-Day Warranty
All main line stoppage work performed by Knockout Plumbing is backed by a 30-day warranty under normal use conditions. If the blockage returns, we come back.
Signs You Have a Main Line Stoppage
Multiple symptoms happening at once is the clearest signal the problem is in the main line — not just one fixture.
-
Multiple slow or stopped drains
Kitchen, bathroom, and laundry drains all backing up at once.
-
Toilet gurgles when you use other fixtures
Running the washing machine or dishwasher causes the toilet to bubble or back up.
-
Sewage smell inside the home
A persistent sewer odor that doesn't go away after cleaning.
-
Water backing up in tub when flushing
Flushing a toilet pushes water up into the shower or bathtub drain.
-
Wet spots or soft ground in the yard
Unusually green or soggy patches near the sewer line path can indicate a break.
-
Sewage backing up in floor drains
Water or sewage surfacing at floor-level drains in laundry rooms or garages.
If you're seeing these signs, stop using your plumbing and call us immediately. Continued use can push sewage back into the home.
Common Causes
-
Tree root intrusion
Roots seek moisture and can crack or penetrate sewer lines over time, causing partial or complete blockages.
-
Grease and debris buildup
Years of grease, soap scum, and debris accumulating inside the line until flow is restricted or blocked completely.
-
Foreign objects
Wipes (even "flushable" ones), hygiene products, paper towels, and other items that shouldn't go down the drain.
-
Aging or collapsed pipes
Older clay or cast iron pipes can crack, corrode, or collapse — especially in homes built before 1980.
-
Bellied or offset pipe
Ground shifting can cause pipes to sag or separate at joints, trapping waste and creating a recurring blockage point.
Not sure what's causing it?
A video camera inspection is the fastest and most accurate way to diagnose a main line problem. We send a camera down the line and show you exactly what's happening — no guesswork, no unnecessary digging.
We pair most main line stoppage calls with a camera inspection so we know whether the blockage needs to be cleared, the pipe needs patching, or there's a larger structural issue.
How We Clear Main Line Stoppages
A straightforward process with no surprises. Here's what to expect when you call us.
-
Assess the situation
We confirm the blockage is in the main line (not a secondary line) and identify access points — typically the cleanout at ground level.
-
Camera inspection (recommended)
We run a camera down the line to locate the blockage, identify the cause (roots, grease, collapse), and confirm there are no pipe integrity issues before clearing.
-
Clear the blockage
We use a cable machine or hydro jetter depending on the type and severity of the blockage. Roots and grease respond better to hydro jetting; hard obstructions to the cable.
-
Verify flow is restored
We run water through the system and confirm full drainage is restored before we leave. Where needed, a post-clear camera pass confirms the line is clean.
-
Advise on next steps
If there's pipe damage, root intrusion, or a recurring issue we'll explain your options clearly — repair, replacement, or preventative maintenance — and let you decide.
Related Services
Main line problems often go hand in hand with these services.
-
-
Sewer Line Repair & Replacement
When a blockage is caused by a broken or collapsed pipe, we handle full repair and replacement.
LEARN MORE -
Video Camera Inspections
See exactly what's inside your sewer line before and after service. No guesswork.
LEARN MORE
Frequently Asked Questions
How do I know if it's the main line or just one clogged fixture?
If only one fixture is slow, it's likely a localized clog. If multiple drains are backing up simultaneously — especially if flushing one toilet affects another fixture — it's a main line issue.
Can I try to clear it myself first?
Chemical drain cleaners are not effective on main line stoppages and can damage older pipes. Store-bought snakes typically don't reach deep enough. If you suspect a main line issue, it's best to call a plumber before making it worse.
How long does a main line stoppage service take?
Most main line clearings take 1–3 hours depending on the severity and cause of the blockage. If we discover pipe damage or need to use hydro jetting instead of a cable machine, it may take longer.
What does the 30-day warranty cover?
If the same main line blockage returns within 30 days under normal use conditions, we'll come back and clear it at no additional charge. The warranty covers the cleared section of line — not new blockages in unrelated areas.
Do I need to be home during the service?
Yes. We'll need access to the cleanout (typically in the yard or near the foundation) and we'll want to run water inside the house to verify the fix. We'll also need someone available to discuss findings if we discover anything unexpected.