Humming sound coming from pipes after toilet is flushed.
What causes this and how do I stop it?

: What you hear is the washer vibrating against the ballcock seat. You can go at this two ways. (1) you can lower the pressure by turning the angle stop located below the tank until the noise stops or, (2) you can shut off the stop and remove the three screws on top and cup your hand over the top and just crack the stop enough to flush out any trash that may be in there. After you do that pull the washer out of its holder and flip it over in its holder and reinstall the top and float. One of the two should do the trick. If not click on back and we will go to plan B. Good luck and thank you for rating my answer. TOM