Ok, iv"e asked a few questions here and still can't figure my problem out. So here is the whole story. Replaced old cast sewer line in house, cleaned the roof vent line to make sure it is open. When you let water out out upstairs tub, the toilet in that room and on the floor below blow bubbles and the one below backs up.After a bit(10 15 min) the toilet drains back out. We replaced the line because it was decyed and open in areas, we never had flushing or draining problems before we replaced the line. I wonder if the vent line is too small diameter for the new sewer line.. Thanks for any help

Hey BS,
Bubbles and backups are not a sign of a venting problem. It's a sign of a blockage. The fact that the toilet eventually drains indicates a partial blockage. Septic tank or city sewer? Rent a commercial sewer machine, (a Ridged K-60 comes to mind) and snake the sewer main downstream from where the toilet backed up. To check where to snake from I would fulus until I saw bubbles or a back up and open op the sewer clean out just outside the house. If the line's full of water then the stoppage is in that line and that's where to start. Good luck, Tom

Tom, we have a septic tank, am going to open tank and get it pumped out. Then will see if that ends problem. If not plan to pull the downstairs topilet and run a power auger through line out to tank. Thanks

"plan to pull the downstairs topilet and run a power auger thru line out to tank."

Don't pull the toilet. Go in through the outside clean out. Pulling the stool and snaking from the bathroom is dirty, messy and unnecessary. Regards, tom

Tom there is no clean out down stairs.

Tom there is no clean out down stairs.

By code we are mandated to install a clean out on the sewer line, brought to grade and not over 18" from the house foundation.
This is located where the sewer exits the house. It may be under a few inches of dirt but if you probe around the side of the house the septic tank's located I'm certain you'll find it. Pulling a toilet is a hassle you don't need when there's a clean out handy. Good luck, Tom

Apparently these codes weren't in effect in 1920 when my house was built, I can find no cleanout. The previous owner knows of no clean out either.

Apparently these codes werent in effect in 1920 when my house was built, i can find no cleanout. The previous owner knows of no clean out either.

My fault, I only go back plumbingwise to the 40's. If this were my call I would see if there was a roof vent I could come down. Only as a last resort would I pull the toilet and snake through the closet bend. Regards, Tom

Tom, got the tank pumped, it was full. Also there was an obstruction between the house and the tank, We went in from the tank side and opened it up.. Everything working fine now.. Except I need to replace 2 sections of the lid. Will do that asap. Thanks for the help!

Tom, just to keep you up dated. Line from the house to the tank was plugged.Ran auger in from the tank to the house, got a slug out of the line. Will keep an eye on it for a few days to see if problem is completely gone. Also going to replace the line from the house to the tank,as it is old cast iron, and also put a cleanout inline to make it easier in the future. Thanks for all your help..

Tom, just to keep you up dated. Line from the house to the tank was plugged.Ran auger in from the tank to the house, got a slug out of the line. Will keep an eye on it for a few days to see if problem is completely gone. Also going to replace the line from the house to the tank,as it is old cast iron, and also put a cleanout inline to make it easier in the future. Thanks for all your help..

Thanks Skinner,
We always like to hear a happy ending. If we can ever be of service again just call on us. Good luck, Tom