A sewer backup means waste water that should be leaving the property is coming back into it. It is a health hazard as well as a plumbing problem, and the single most useful thing you can do before anyone arrives is stop putting water into the system — no taps, no toilets, no washing machine, no dishwasher.
Need this looked at?
Tell us your town or ZIP code and what is happening. We route the call to an independent contractor covering that area.
Call (888) 855-8790
How a contractor actually diagnoses it
- They confirm it is a backup and not an overflow. A backup pushes water up through the lowest fixture; an overflow comes from the fixture itself.
- They check whether it is one fixture or the whole property. Whole-property means the main line or the municipal connection.
- They open the cleanout. Standing water at the cleanout confirms the blockage is downstream of it.
- They cable or jet from the cleanout, then camera once flow returns to identify the cause.
Three ways this actually fails
Blocked main line
The most common cause. Roots, grease or a structural defect stop flow, and the lowest opening in the house becomes the relief point.
Municipal main surcharge
During heavy rain the public main can fill faster than it drains, pushing water back up private laterals. Nothing is wrong with your pipe — which is why a backflow prevention valve, not a cleaning, is the fix.
Failed backwater valve
Where a valve is fitted, a stuck or debris-jammed flapper can hold waste in the property. Cheap to check, easy to miss.
Signs this is urgent rather than annoying
- Any raw sewage inside the property — stop water use and call
- Backup happening during or right after heavy rain (points to a surcharge, not your line)
- Multiple fixtures on the lowest floor affected at once
- Standing water reaching electrical outlets, a furnace or a water heater — treat as an electrical hazard too
What it costs
Published third-party ranges shown so you can sanity-check a quote. Not our prices, not an estimate, not a quote.
| Job | Published national range | Source |
|---|---|---|
| Main sewer line clearing | $175–$800 | HomeGuide |
| Sewer line clog | $100–$800 | Angi |
| Camera inspection | $125–$500 | HomeGuide |
Published national ranges, shown for educational context only. These are not quotes and they are not our prices. Sources disagree with each other — that spread is real. Only the contractor who sees your line can price your job.
Full cost guide, by fixture and by method →
Questions people ask
How do I find sewer backup near me?
Call the number on this page and give us your town or ZIP code. We match it against partner coverage and connect you with an independent licensed contractor who works that area. We do not charge you anything — the contractor sets their own price.
What should I do in the first five minutes?
Stop all water use in the property, keep people and pets away from the standing water, and if it is anywhere near electrical outlets or an appliance, do not wade in — treat it as an electrical hazard as well as a sanitary one.
Does homeowners insurance cover sewer backup?
Standard homeowners policies usually exclude it; most insurers sell water backup or sewer backup as a separate endorsement. Coverage varies widely, so check your specific policy — we are a referral service, not an insurer, and cannot tell you what yours covers.
Is it my responsibility or the city's?
If the blockage is in the lateral between the house and the main, it is normally the property owner's. If the public main has surcharged, it is normally the municipality's. A camera inspection is what establishes which.
Why did it happen right after heavy rain?
That pattern usually means the public main filled faster than it could drain and pushed back up your lateral, or that storm water is entering your sanitary line through a defect. Both are worth a camera.
Can I just bleach it and move on?
No. Bleach addresses smell, not cause. A backup that happened once will happen again, and the second one is usually worse because nobody stopped using water in time.
How fast can someone come out?
Backups are treated as urgent by most contractors, but availability belongs to them, not to us. Call and we will tell you honestly what coverage looks like right now.
What is a backwater valve?
A one-way flap fitted in the lateral that closes when flow tries to reverse. It is the standard defence against municipal surcharge and is worth asking about if your backup came during heavy rain.