We have a bi-level home. After my shower today I went downstairs and heard water in the bathroom and realized the toilet overflowed. Never use this bathroom so I new it couldn't have suddenly been the toilet. My husband realized the toilet is overflowing when the shower is on upstairs. What would cause this and how is it fixed?

Your drain line downstream of the toilet is partially blocked. The shower water head downward via a 2" pipe but the blockage can't handle it so it starts to fill the drain pipe to the point where it overflows the toilet which is the low point in the house. Don't bother trying to rod upstairs, the blockage is at your lowest level so look for a clean out and use at least a 1/2" snake.

Thanks so much. My husband is good at many things, but plumbing is not one of them!

There are several plumber here on a daily basis and a few installers like me. We are always ready to help you and your husband, we've done it all in our sleep.

Hello, how do you go about locating and unclogging the clean-out? We have the same problem with a downstairs toilet that overflows seemingly due to an upstairs tub/shower. I have plunged the toilet and used various chemicals and though it seems to clear (can flush it a few times without any problem but then it won't flush properly anymore) we still have the problem. The sinks in the nearby kitchen are also affected. Help!

Hello, how do you go about locating and unclogging the clean-out? We have the same problem with a downstairs toilet that overflows seemingly due to an upstairs tub/shower. I have plunged the toilet and used various chemicals and though it seems to clear (can flush it a few times without any problem but then it won't flush properly anymore) we still have the problem. The sinks in the nearby kitchen are also affected. Help!
Hi ALR57 and welcome to The Plumbing Page atAskMeHelpDesk.com
Are you on a septic tank or city sewer? Sounds like you have a partial blockage downstream from the down stairs toilet. The solution would be to pull the toilet and snake the open line. Good luck. Tom