Help! Our downstairs toilet is bubbling up and splashing out. We live in a two story house, upstairs has two showers, two toilets, three sinks. Downstairs has one toilet, two sinks and one washer. I did several tests to see what was causing it, here are the results.

Test one:
Draining upstairs sinks, no bubbling.
Draining upstairs tubs, no bubbling.
Flushed upstairs toilet (directly above), slight bubbling.
Flushed upstairs toilet (other side of house), significant bubbling, splashing out.
Drained sink next bad toilet, no bubbling but water was moving as well as significant draining sound behind wall.

Test two:
Filled upstairs toilet (other side of house) with baking soda and vinegar (google suggestion) waited one minute then flushed. Downstairs toilet bubbled and splashed and I thought I got wiff of vinegar in the air.

The bubbling is significant, the seat and floor get visibly wet.

Internet suggests flushing vents (on roof) or snaking from toilet to the street. Getting up on our roof is not an option as it is about 30 feet and we don't have a ladder that high. Sounds like we need a plumber? If that is the case, how do I know they are being honest and not trying to upsell me on a service I don't need. If they say its tree roots and want to dig the front yard up, how will I know if that is true?Should I tell them exactly what I want/need done or let them lead?

Thanks!

A few more details

House was built in 2007
Not on slab, small crawl space available
Bad toilet does flush, but fairly slow
When upstairs toilet is flushed, it mostly just bubble downstairs, I don't notice it draining out at all.

Would renting a snake be beneficial?

Hi lyonpo,


Would renting a snake be beneficial?

This is what I am thinking, you have a partial blockage down stream of the bubbling toilet. Do you have access to cleanouts?

Hang tight for the plumbing experts, they'll know exactly what to do. Good luck