Is Your Main Sewer Line Clogged? Signs and What to Do
Short answer: If more than one drain is slow at the same time, water comes up in the tub or shower when you flush, or toilets gurgle, the clog is probably in the main sewer line. Stop using water and have a licensed plumber clear it. Cleaning a main line typically runs $100 to $800 nationally; a broken line costs more.
Last updated: November 14, 2026
Texas requires a license for plumbing work. Look up any plumber in the state's public database before you hire.
The drains in your house come together in one main line that carries everything out of the house. When that line clogs, the problem shows up in more than one place, and it gets worse every time someone runs water.
One clog or the main line?
| What you notice | Probably |
|---|---|
| One sink or tub is slow; everything else drains fine | A clog in that drain |
| Several drains are slow at the same time | The main line |
| Water comes up in the tub or shower when you flush | The main line |
| Toilets or drains gurgle after water goes down | A blockage further down the line |
| Sewer smell inside the house | A blocked or damaged line |
| A wet, smelly spot in the yard | A blocked or broken line outside |
These are the warning signs Angi lists for a clogged sewer line, in an article reviewed by a journeyman plumber.
What to do right now
- Stop using water. No flushing, no showers, no washer, no dishwasher. Everything you run has nowhere to go but back up.
- Keep people and pets away from any water that came back up. Sewage carries harmful bacteria.
- Stay away from electricity if the water has reached outlets or appliances.
- Skip the drain chemicals while water is backing up, and tell the plumber if you already used any.
- Get a licensed plumber to clear the line.
Texas requires a license for plumbing work. Look up any plumber in the state's public database before you hire.
What a plumber will do
- Clear the line with a drain machine or a water jetter, usually through a cleanout.
- Run a camera through the line if it keeps clogging, to look for roots, a sag or a break.
- Give you a written estimate if the line needs repair or replacement.
Ask to see the camera video. It shows you what the plumber saw and makes it easier to compare a second opinion.
What it costs
National figures:
- Clearing a drain: about $241 on average, most between $147 and $345 (HomeAdvisor).
- Cleaning the main line: typically $100 to $800 (HomeAdvisor).
- Repairing or replacing a sewer line: most jobs between $1,200 and $6,000 (Angi).
Prices in Laredo can be different; the plumber confirms the price before starting. Angi also notes that most standard homeowners policies don't cover sewer line replacement, though some insurers offer it as an add-on, so it's worth checking your policy.
Keep the main line flowing
Angi's prevention list:
- Only toilet paper in the toilet. Wipes, even "flushable" ones, paper towels and hygiene products cause clogs.
- No grease down the kitchen sink. Let it cool, wipe the pan and throw it in the trash.
- Watch your yard for wet or unusually green spots over the line.
- Have the line checked if clogs keep coming back.
Questions to ask the plumber
- Is the clog in the main line or in one drain?
- Did you find roots, a sag or a break? Can I see the video?
- If it needs repair, what are the options and the price of each, in writing?
- Does the job need a city permit?
- What's your license number? Look it up before work starts.
Related
Before you hire, check the license
Texas requires a license for plumbing work. Look up any plumber in the state's public database before you hire.
Sources
- Angi, "Signs of a sewer line problem" (reviewed by a journeyman plumber, Oct. 12, 2023)
- This Old House, "What to do when your sewer backs up" (updated Mar. 10, 2026)
- HomeAdvisor, "Unclog drain cost" (2025)