Gurgling Tub

[DIYMike]

Just removed and reinstalled a soak tub. I'm using a Watts trip lever drain asssembly (used to have to reach into the tub to pull the plug). Anywho...

Now, when draining, it gurgles. I don't remember if it did before. When I put my hand over the drain (to slow down the drain flow) the gurgle stops.

I tried to remove the trip lever piece but that didn't help.

What causes gurgling or air suck in a tub drain?

[Plumber2000]

Sounds like a real good draining tub, I've encountered tub that make a gurgling sound before, not cause it was a slow draining tub or clogged vent, but just a good draining tub.

If it's consistent sounds during the draining of it then there may not be any problems with it.

Some tub drains can make this sound and be no problems.

[hj]

That is the water draining so fast that it is aspirating water down the overflow pipe. It is the sound we listen for to know whether the tub is draining to its maximum.