My house is a 1929 colonial. We installed new toilets when we moved in (1 in a second story full bath and 1 in a first floor half bath) and after that point, we would get gurgling in the tub upstairs occasionally and in the half bath sink after we flushed the toilet. A plumber told us an AAV in the sink would fix the problem in our upstairs bathroom. That basically left the gurgling in the tub instead of the sink. If we let the water run in the tub and sink it would take multiple flushes to hear the gurgling in the tub and sink after being flushed. So we’ve had to run water if we heard it so it goes away. We had a drain service clean our mainline and flushed our vent stack with a hose. I flushed it a lot and didn’t hear anything until the next morning, I was flushing again to see if it was fixed and we heard the same gurgle from the tub. I did the same thing in the half bath, but hadn’t heard any gurgling from the sink yet.

We have not noticed any backing up or slow draining fixtures.

What could be wrong and how can we fix it?

1 Answer 1


This is a classic sign of a clogged vent (if it's a new behavior) or an improper/inadequate vent (if it's always been this way.)

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