Stop all water
Tell everyone in the building not to flush, shower or run appliances.
Main sewer line clogged and several drains backing up?
When the main sewer line clogs, every drain in the building has nowhere to go, and the lowest drains back up first. Stop all water use, then call 833-877-1717. RepairNowUSA connects the request. An independent plumber or drain service clears the line.
Am I in the right place?Yes if toilets, tubs, showers or floor drains back up together, or water comes up in one fixture when another is used.
Is this urgent?Yes. Every flush or shower adds to the backup until the line is cleared.
What do I do next?Stop using all water and call 833-877-1717 with the ZIP code and where it is backing up.
Sewage already on floors: sewage backup cleanup. Roots: tree root removal.
RepairNowUSA editorial review · Last substantively reviewed October 13, 2026 · Review standards
What to do
Clear access to the cleanout
Move items away from the basement cleanout or find the outside cleanout cap. Do not open it yourself if water is backed up; it can release sewage.
Keep away from sewage
Keep people and pets out of affected rooms.
Opening a cleanout can release sewage
A cleanout under pressure from a backed-up line can gush when opened. Leave it for the plumber, who can open it safely and clear the line from there.
Common causes
Wipes and grease
The most common cause. "Flushable" wipes do not break down like toilet paper.
Tree roots
Older clay and cast-iron lines. See tree root removal.
Bellied or broken pipe
Low spots catch waste. See sewer line repair.
City sewer backup
If neighbors are affected too, contact the sewer utility.
What to have ready when you call
- Property ZIP code, home or business
- Which fixtures back up
- Whether sewage is inside
- Cleanout location, if known
- Any prior backups or sewer work
- Number of units or restrooms, for businesses
What happens when you call RepairNowUSA
- Describe what is happening in plain words and give the property ZIP code. You do not need to know which trade to ask for.
- RepairNowUSA checks for a participating independent provider who handles main sewer line clearing in that area.
- If one is available, you are connected. The provider confirms timing, access, scope and price with you before any work.
- The provider, not RepairNowUSA, diagnoses and performs the repair.
RepairNowUSA is a referral and connection service. Provider availability and response times vary by location, time and demand, and are not guaranteed. Before you approve work, ask what was found, the price, the timing and what is not included.
Call 833-877-1717Main line clog questions
How is a main sewer line cleared?
Usually with a cable machine (snake) or hydro jetting through a cleanout. A camera may be run afterward to check for damage.
Can I call about a main line clog at night?
Yes. You can call 833-877-1717 at any time, including nights, weekends and holidays. Whether an independent provider can come out right away depends on your ZIP code, the time and provider capacity, so availability is not guaranteed.
Will it happen again?
If roots or a damaged pipe caused it, likely yes. A camera inspection helps decide whether repair is needed.
Can I use the toilet while waiting?
No. Anything you flush adds to the backup.
Is cleanup included?
Clearing the line and cleaning up sewage are usually separate jobs. Tell the operator if sewage came inside.
Authoritative references
These public sources give general safety context. They do not replace an on-site evaluation, and RepairNowUSA does not perform the work.