A few minutes after using the up-stairs sink in my new home a dripping noise can be heard from the drain pipe. The noise goes on for 10 to 20 minutes. There is no visible leak anywhere. I took the elbow off and the dripping continues. It appears the noise comes from the pipe inside the wall. Could construction debris be caught inside the drain pipe? Any ideas how to fix it?
There are two sinks in the master bathroom. It does not matter which one I use, there will be this dripping noise.
I have removed the stoppers and disassembled all pipes from both sinks to the wall and could still hear the dripping from somewhere inside the pipe going down the wall.
I used a long bottle brush and tried to clean the inside drain of any possible debris.
No such luck. I put everything back together, but, just like before, the dripping noise starts a few minutes after using an upstairs sink. There is no leak anywhere, just this noise driving me bananas.