How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Rick Your Own Question
Rick, Construction Supervisor
Category: Plumbing
Satisfied Customers: 19055
Experience:  Licensed Master plumber with 40+ yrs. experience.
Type Your Plumbing Question Here...
Rick is online now
A new question is answered every 9 seconds

Terrible vibration and humming noise (seems to come from wall)--it

Resolved Question:

Terrible vibration and humming noise (seems to come from wall)--it goes AWAY when I flush the toilet. Any idea what is wrong?
Submitted: 6 years ago.
Category: Plumbing
Expert:  Rick replied 6 years ago.
HiCustomerbr />
The noise you describe is usually caused by a faulty pressure reducing valve on the water main or a back flow preventer somewhere on your water piping. Often the problem back flow preventer is the one on the end of an outside faucet. Sometimes just turning the outside faucet off will stop the noise. Another common problem back flow preventer is the one on an irrigation system.
Customer: replied 6 years ago.

sounds more involved than I thought. Here's more info:


In the guest bathroom, the same problem occurred 3 years ago and the landlord changed the tank fill valve, he tells me. Since I've lived here, no problem in that bathroom, however, the MASTER bath is where this problem started occurring...I was thinking it could be the same problem, as the toilets are both 35 years old, purchased at the same time. There is NO running of water, etc., so the fill valve doesn't sound like a 'fix'. The noise and vibration is only stops when I flish the toilet in that bath. If I turn on the shower or faucets, the sound wavers a tin y bit.


Do you still think your original answer is correct?

Expert:  Rick replied 6 years ago.
It is also possible that the fill valve in the toilet is the culprit but this culprit is more common when the noise happens when the toilet is filling. Unlike your noise which stops when the toilet is filling. Your additional info doesn't change my original answer.
Rick and 2 other Plumbing Specialists are ready to help you
Customer: replied 6 years ago.

The outside faucets have not been used for 3 months.


The noise does NOT happen when the toilet is flushed or I use any water in the just starts up in the middle of the night, evening, whenever.


the only time it STOPS is when I flush the toilet in that particular bathroom.

Expert:  Rick replied 6 years ago.
The outside faucets were just one possibility. I listed other possibilities. All I can do from here is give you possibilities since I can't check out your problem in person.

I understand that the noise stops when you flush the toilet. My response indicated that replacing the fill valve was not a likely fix in this case. If you rent then your landlord should address the problem or call a plumber who can.

Related Plumbing Questions