0

When the bathtub water (after a bath for my toddler) is draining,why does the toilet bowl water move?

This is a new home and this toilet recently had problems with the tank not filling and therefore not flushing well.

2
  • How does the water move? Sloshing around? Monstrous waves? Ripples from vibrations?
    – Damon
    Dec 17, 2015 at 6:30
  • More like rippling (water moving vertically up and down) that immediately stops as tub is drained
    – Starfish
    Dec 17, 2015 at 14:21

1 Answer 1

3

All these lines are connected, but it's not easy to say how without inspecting under the floor. I'd say there's a good chance the shower, possibly sink too, are connected to a one vent, and that drain is a wet vent for the toilet where they join further down stream. Then everything runs down to a main stack. That would be a fairly typical setup.

If you see bubbling in the toilet from the bath, or hear gurgling in the tub from the toilet, you may have a problem with a blocked vent. Otherwise, some movement can be expected. As the water rushes past the wye connection to the toilet, it causes some pressure changes pushing the water up or pulling it down on the other side of the trap (the toilet bowl). You're also likely to see that on a windy day just from wind blowing over the vent pipe on the roof. Other traps do the same thing, but you can't as easily see them.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.