Note to readers: This post was updated on July 09, 2026 to reflect current best practices for main line maintenance and remove outdated pricing. We refreshed the details below so the advice reflects how we approach this work today.
Your main sewer line carries wastewater from every fixture in your house to the city sewer or septic system. It’s also the pipe most homeowners forget about — until it backs up into a shower or floor drain at the worst possible time.
Why the Main Line Clogs
Unlike a sink or shower drain, the main line runs underground, often under a yard with mature trees. Over time, tree roots find their way into old pipe joints, grease and soap buildup narrows the inside diameter, and paper products or debris get stuck on rough spots. Homes with cast iron or older clay pipe are especially prone to this — see our comparison of cast iron vs. ABS plastic sewer pipe for context on why older materials fail faster.
Signs Your Main Line Needs Cleaning
- Multiple drains backing up around the same time
- Toilets gurgling when you run the washing machine or dishwasher
- Sewage smell near your cleanout or yard
- Slow drainage that chemical cleaners don’t fix
If you’re seeing these signs, read our full breakdown of signs your main sewer line is failing.
What Professional Main Line Cleaning Involves
A technician runs a motorized cable down the line to break up and clear whatever is restricting flow. For lines with heavy grease or root intrusion, hydro jetting is usually more thorough than snaking alone because it scours the full diameter of the pipe rather than just punching a hole through the clog.
Why Annual Service Makes Sense
Cleaning your main line once a year, before problems show up, is far cheaper than an emergency call after a backup floods a bathroom or laundry room. It also gives your plumber a chance to spot early warning signs — root intrusion, bellied pipe, or corrosion — before they turn into a full sewer line replacement. If it’s been more than a year since your line was serviced, or you’ve never had it done, it’s worth scheduling before the next rainy season.
Western Rooter & Plumbing has been clearing and maintaining main lines throughout the San Gabriel Valley for decades. Give us a call if you’re not sure whether your line needs attention.
