Bath tub Backs up

[dinghoa]

Hi,
when I have a bathroom sink full of water and go to drain it, it backs up
into the tub. If I let the water out slowly it won't back up.

The tub, sink, and toilet are on the same wall.

I have put drain cleaner but it never gets better.

Any help here? Thanks

[DUNBAR PLUMBER]

You will have to get a drain cleaning machine, remove the overflow cover on the tub and access the drain to remove the clog.


This will remove the obstruction which will probably open up the sink as well, since the two are connected by the way the tub is backing up.