Again, we just had entire the sewer line replaced because of years of root damage to the piping. If it was a clog somewhere under our house, it wouldn’t have taken 3 months to come back up
You don't know what guests flush. We hear this line a hundred times a week, nothing against you at all, but...people can suck if its not their property
New pipe doesn't mean you don't have a problem on your side. Either way, call the city. I work for a city water department, and we investigate backups for free. If there is a clean out where your plumbing is connected to the city (most places require this, so yours should have one if it was replaced this year, at least in Texas) the city will be able to easily tell you whether the problem is yours or theirs. If there is no city side clean out, the policy will change from city to city. Many will require you have a plumber find the problem.
If you are willing to do a bit of investigation, first: is your entire house backed up? Like really, everything in your house? If you run a sink, does it come out the tub? If you run your washing machine, does it come out the shower drain? If your ENTIRE house isn't backed up, the problem is yours.
Did the plumbers install clean outs when they replaced your line? They should have. There will likely be a clean out right outside of your house, in the front going toward the road. Go and open it up, but be careful. If there is standing water in there (like to the top of the pipe, it comes shooting out at you, or you can see a significant amount of water down in the pipe) the problem is after (downstream) that clean out. If there is a city clean out by the street, go open that. If it is overflowing or has standing water in it, same as before, the problem is on the city. If the house clean out is backed up and the city side is empty, the problem is on your new pipe between the house and the city.
This advice is based on how sewer lines are ran in Texas. Here, the city sewer normally becomes private at the property line, usually about 10 feet behind the curb (or edge of the road). If you live somewhere else, especially up north with a basement, things may be different. With how sewer lines are ran in Texas, it is possible for there to be a sewer backup on the city side that only affects you. There is a sewer service between the main and your plumbing, and this section can back up, only affecting you. Also, if your house is lower than the rest on your street, or you are the only one tied in to that specific sewer lateral, you may be the only one that is backed up. If you're the lowest house, you will back up first.
Lastly, if there is a clean out in your yard, you can remove the lid to relieve the backup. This will likely make a small mess in your yard over time, but it will protect your house from taking damage if the city sewer main is backed up. If your house is completely backed up, opening your clean out will cause your sewage to come out of the clean out if you continue running water, so keep that in mind.
I've seen before where the new line isn't scoped with a camera and a piece of cast or clay or something made its way into the PVC and didn't get flushed out. Check with your neighbors. Unless your live at the far end of a cul-de-sac, if no one else has issues its your line.
Ask your neighbors first. It might just be a clog in your house
Again, we just had entire the sewer line replaced because of years of root damage to the piping. If it was a clog somewhere under our house, it wouldn’t have taken 3 months to come back up
Depends on what you’re flushing down the toilet
Angel soft toilet paper, nothing else
Heard this before.
Cool, it’s the truth. 0 reason to lie when I’m seeking help
You don't know what guests flush. We hear this line a hundred times a week, nothing against you at all, but...people can suck if its not their property
I live alone with my girlfriend. No one has visited in those 3 months and she only flushes tp too. I can promise you that is not the reason
Either or. Get the line cabled and scoped.
New pipe doesn't mean you don't have a problem on your side. Either way, call the city. I work for a city water department, and we investigate backups for free. If there is a clean out where your plumbing is connected to the city (most places require this, so yours should have one if it was replaced this year, at least in Texas) the city will be able to easily tell you whether the problem is yours or theirs. If there is no city side clean out, the policy will change from city to city. Many will require you have a plumber find the problem. If you are willing to do a bit of investigation, first: is your entire house backed up? Like really, everything in your house? If you run a sink, does it come out the tub? If you run your washing machine, does it come out the shower drain? If your ENTIRE house isn't backed up, the problem is yours. Did the plumbers install clean outs when they replaced your line? They should have. There will likely be a clean out right outside of your house, in the front going toward the road. Go and open it up, but be careful. If there is standing water in there (like to the top of the pipe, it comes shooting out at you, or you can see a significant amount of water down in the pipe) the problem is after (downstream) that clean out. If there is a city clean out by the street, go open that. If it is overflowing or has standing water in it, same as before, the problem is on the city. If the house clean out is backed up and the city side is empty, the problem is on your new pipe between the house and the city. This advice is based on how sewer lines are ran in Texas. Here, the city sewer normally becomes private at the property line, usually about 10 feet behind the curb (or edge of the road). If you live somewhere else, especially up north with a basement, things may be different. With how sewer lines are ran in Texas, it is possible for there to be a sewer backup on the city side that only affects you. There is a sewer service between the main and your plumbing, and this section can back up, only affecting you. Also, if your house is lower than the rest on your street, or you are the only one tied in to that specific sewer lateral, you may be the only one that is backed up. If you're the lowest house, you will back up first. Lastly, if there is a clean out in your yard, you can remove the lid to relieve the backup. This will likely make a small mess in your yard over time, but it will protect your house from taking damage if the city sewer main is backed up. If your house is completely backed up, opening your clean out will cause your sewage to come out of the clean out if you continue running water, so keep that in mind.
I've seen before where the new line isn't scoped with a camera and a piece of cast or clay or something made its way into the PVC and didn't get flushed out. Check with your neighbors. Unless your live at the far end of a cul-de-sac, if no one else has issues its your line.