Banging after toilet flush

[Keith N.]

I've seen this problem discussed before in this NG but the situation here is a little different than what I've read.

After every flush in the 2nd floor bathroom in our condo (built in '93), I hear a loud deep clunk simultaneous with gurgling in the adjacent tub drain immediately after the bowl water is flushed (ie not related to the tank fill).

Any thoughts? Is the toilet clogged? Everything flushes fine as far as I can tell though.

Thanks, Keith

[Speedy Jim]

Gurgling in the tub drain strongly suggests a venting problem (e.g., clogged vent). Just guessing, but the clunk may be the "slug" of water hitting a turn in the drain.

Is the condo assoc responsible for this kind of problem?

Jim

[Joseph Meehan]

I agree with Jim. It will also mean that you are at risk of getting sewer gas into your bathroom through the bathtub or other drain that is being compromised by the bad vent.

[Jay]

On a similar note (no pun on the slam and gurgle :+):

Our second floor toilet does the same thing, but no gurgle. The main vent is no more than 1 foot from the toilet. I'm not sure fo the exact route plumbing bebeath the floor, but the toilet shoudl have a clear shot right down the main standpipe (vent) (4") and into the sewer. The standpipe goes right out the roof and is very clear.

When the flapper closes on the toilet, the toilet makes a ferocious sucking sound. The sink and tub in the room are OK.

What is making the toilet "slam" shut, and how can I stop it?

Thanks for any clues...

Jay

Joseph Meehan wrote:

[Joseph Meehan]

I would suggest taking the top off the tank and watch to see and hear what is happening. I would guess it to be either the flapper valve or too high a water pressure for the fill valve.