Main sewer line backed up right after moving in
A sudden main sewer line backup immobilizes every drain, toilet, and appliance in the house while forcing homeowners to wait indefinitely for an emergency technician. Dealing with active flooding with young kids in the home makes it difficult to secure immediate repairs, document the damage properly, and figure out whether warranty coverage or insurance applies.
What the numbers show
Counted from the threads quoted below. How we count
- Most of it landed at once — the busiest month was September 2026, with 15 people.
- This comes up 15.9× more often in r/Plumbing than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1checking home insurance policies for backup coverageDid this help you?
- 2reading builder warranty fine print and contacting emergency hotlinesDid this help you?
- 3getting buckets ready for toilets and documenting damages with photos and videosDid this help you?
- 4hiring a plumber to perform a sewer scope and save the videoDid this help you?
- 5Drying water immediately and placing something underneathDid this help you?
- 6Running a snake and using a camera to inspect the pipesDid this help you?
- 7Hiring an independent plumber to re-inspect and camera the lineDid this help you?
- 8Getting hydrojetting treatment done independentlyDid this help you?
- 9Hiring a professional plumber to snake the lineDid this help you?
- 10Renting a 100ft snake from Home Depot to clear the clog yourselfDid this help you?
- 11Running a camera inspection to check for roots or pipe damageDid this help you?
- 12Monitoring the sewer line for clogs or slow drainageDid this help you?
- 13Hydro-jetting the pipe periodically to clear sedimentDid this help you?
- 14Waiting for the yard to be dug up to find out the causeDid this help you?
- 15Running water into the drain to test for soft stoppagesDid this help you?
- 16Renting a snake to clear outdoor debrisDid this help you?
- 17Using a bladder bag to blow out the clogDid this help you?
- 18Borrowing a camera from a plumber friendDid this help you?
- 19Replacing anything that can absorb waterDid this help you?
- 20Calling homeowners insurance to have a remediation company salvage or replace items as neededDid this help you?
- 21using an auger or snake to clear the drainDid this help you?
- 22calling a plumber to scope or hydrojet the pipesDid this help you?
- 23Tearing out the underground line and redoing it properly.Did this help you?
- 24Using a garden hose with a drain bladder to clear the blockageDid this help you?
- 25Renting a heavy-duty drain cleaning machine from a home improvement storeDid this help you?
- 26Calling a professional plumber or drain cleaning serviceDid this help you?
- 27Wiping the sink out with paper towels and bleachDid this help you?
- 28Running water to see if it drains properlyDid this help you?
- 29Snaking the drainDid this help you?
- 30Checking the sewage ejection pumpDid this help you?
- 31Using a 20-foot snake down the cleanoutDid this help you?
- 32Releasing the pressure at the outside cleanoutDid this help you?
- 33Letting the system rest for a day to see if it drains normallyDid this help you?
- 34minimizing water usageDid this help you?
- 35avoiding running laundry or the dishwasherDid this help you?
- 36taking very short showersDid this help you?
- 37Calling a local reputable plumber or independent drain cleaning company instead of large national chains to snake and scope the drains.Did this help you?
- 38Questioning the construction company's explanationDid this help you?
- 39Trying to investigate whether it is caused by tenant misuse or a structural defectDid this help you?
- 40Proceeding with the home purchase without seller concessionsDid this help you?
- 41Walking away from the real estate contractDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Found this in my shower this morning.”source ↗
“Your main sewer drain maybe clogged.”source ↗
“Flush your toilet, does it come up in the shower? Sewer clog.”source ↗
“I smelled an absolutely rancid smell from behind the bar. Pull stuff out and find this.”source ↗
“The main thing in the drain resembled food or a dead animal but basically disintegrated as I tried to grab it.”source ↗
“My basement toilet backed up and flooded my suite for the 3rd time this year.”source ↗
“I took a shower last night and my water sensor went off. I found this happening in the basement. Thankfully it drained but I am going to need to fix this.”source ↗
“Our bottom floor toilet and tub are leaking water.”source ↗
“Upstairs toilet and shower drain just fine, but then we get water flowing downstairs.”source ↗
“Blockage in our front yard service line from the sump ejector.”source ↗
“First time home owner and clueless. Looks like we have a backup-water had overflowed during middle of night.”source ↗
“Before we involve plumbers, what should we do?”source ↗
“How bad is this drain leading to the sewer? I was told root intrusion and severely back pitched.”source ↗
“I’m a first time home owner only been living here for 6 months.”source ↗
“Thanks for your advice and I’m sorry if I broke any rules I just am very nervous about this”source ↗
“Sellers says they won’t fix since they never had issue with the sewer, so it isn’t a real problem.”source ↗
“Some of my pipes were rusty and while the guy left to get a part, I heard water start to flow out. It was stable before.”source ↗
“I have also been having issues with my dishwasher draining - the motor and dishwasher itself is fine, it will start to drain but senses overflow and stops.”source ↗
“I had a similar issue with the dishwasher a couple months ago, and a week later replaced the motor thinking it was that. Dishwasher ran fine for a few weeks, then stopped draining again.”source ↗
“Sewer main backed up on 4/24. I had a professional plumber come to snake it.”source ↗
“I had backups again on 6/22, 8/5, and now 9/10.”source ↗
“The backups on 6/22 and 8/5, I rented a 100ft snake from Home Depot to take care of it but the latest one I called a different plumber because I didn't know if there was something bigger happening.”source ↗
“I’m under contract on a house (MI) and had a sewer scope done.”source ↗
“The inspector has now confirmed there is a belly/low spot from about 5–18 ft, caused by inconsistent slope.”source ↗
“Any plumbers here, would a ~13 ft belly with more than half-pipe standing water be considered a serious issue, or something you would monitor unless clogs/slow drainage start happening?”source ↗
“This is an incident that has happened several times in the building and is causing quite a bit of concern. There has been water backing up into several apartments, leaving them completely flooded and causing severe damage to the affected floors”source ↗
“The main concern is that we don't know whether we can trust their explanation, since this is a recurring issue and it doesn't seem like they are willing to take responsibility for any potential structural or construction-related problem.”source ↗
“Do you think I should trust the explanation or look for a more thorough analysis?”source ↗
“If you took possession of a house and within a month, the main sewer line flooded, would that be part of the builder’s warranty?”source ↗
“With the main sewer line being part of our home’s internal plumbing system, this means that every toilet, sink, shower, and drain in the house is affected. We shut off the water. But it’s 830pm and we have young kids.”source ↗
“We called the emergency line and they said they will dispatch a technician to take a look. No real time line. He will get here when he gets here.”source ↗
“Anything we should do? We took pictures and videos. But anything else we’re missing?”source ↗
“About 1 week ago after running the dishwasher and clothes washer a spot in my yard started pooling(around connection point of septic tank and drainfield) and drained after a couple of hours.”source ↗
“Now yesterday we ran a load of laundry in the morning, and when it came time to shower in the evening both tubs backed up, with no pooling in the lawn this time.”source ↗
“I was hoping to have a little more time to shop around, but seeing as i am unable to use any plumbing fixtures i feel i dont have the time”source ↗
“in the weekend from hell our sewer backup into part of our basement. i got got the drain cleared pretty quickly, but now I’m more confused about the cleanup than the plumbing.”source ↗
“we have a lot of stuff that is sentimental as well as the obvious house stuff that was touched by the sh*t. how aggressive does cleanup need to be when sewage only touched a small area? is like drywall baseboards and laminate automatically considered unsalvageable?”source ↗
“Just trying to figure out what route to take so I'm not wasting money.”source ↗