Return to the Plumbing Forum | Post a Follow-Up

Pipes 'hum' when toilet is flushed and water pressure is low

Posted by cecilpenny (My Page) on
Mon, Nov 9, 09 at 10:08

Please help - our home is only 5 years old. I came home from a deployment to find our plumbing 'humming' whenever we flush a toilet. The husband didn't notice because he wasn't away for a year like I was...(oops). Additionally, our water pressure seems to have taken a dive. We do not know how to check our water pressure level and we certainly don't know why the plumbing makes noises. We do have a water softener which we put in when our home was built. Any assistance you can provide is greatly appreciated.

Follow-Up Postings:

RE: Pipes 'hum' when toilet is flushed and water pressure is low

Could be a number of things. Are you on a well or on city water? What happens when you take a shower or use the water for other purposes? Is there a difference when you use all hot water rather than all cold water? Have you done any maintenance that may be required on the water softener?

You can check water pressure with the help of a $6-7 gauge that screws on to any hose bib (outside hose connection, or possibly inside laundry tub, or clothes washer connection) and can be purchased at most hardware stores.

RE: Pipes 'hum' when toilet is flushed and water pressure is low

TWO possible causes I've personally encountered. The first fix is FREE, the second one is cheap.

1) The air columns in your arrestor tubes have been absorbed over time by the passing water, and the rapid action of your toilet's automatic fill valve is causing water hammer--not just annoying, but damaging to your pipes!

You simply need to drain your pipes and let the arrestor tubes refill with air. You do this by shutting off the water to the whole house, then opening the highest faucet in the house (to let air in), then opening the lowest faucet (to drain as much water down a drain as possible), then lastly, open the very lowest point in the system, which is usually a toilet shutoff valve, or an outside/basement hose bib. (You will need a pan under the toilet shutoff valve.)

When the draining is complete, close all these fixtures. Note that turning the whole-house valve back on will likely kick loose a lot of sediment. This sediment can clog sink faucet aerators, and ruin toilet fill valves... SO, turn on only BATHTUB faucets, as they are full flow, and have no restrictors or screens. Let the tub(s) run until all the spitting and spurting is over, and they're running clear and quiet.

If the problem was water hammer, you should be cured, otherwise on to #2. (Your time has NOT been wasted, as you should do the whole-house drain-down annually anyway, for these very reasons--to clear sediment, and prevent water hammer.)

2) Your toilet fill valve has sand/sediment in it, or some other fault, and needs cleaned or replaced. About $0 to dissassemble and clean, or $7 to replace, ASSUMING you can do-it-yourself. Flushmaster if you want an all-in-one solution.

PS: Thank you for your service to the nation, and WELCOME HOME! (My brother returns from "the 'stans" on Friday.)

Oh, my previous post...

... applied only to your toilet-related humming.

Your drop in water pressure could indeed be caused by your water softener, in-line filter, and similar appliances that serve the whole house. If your softener has valves which allow you to bypass it, that would be a simple test. Please post details on make and model of your wa-wa softener.

I assume your outdoor hose bibs are NOT on the softener, so that would be a good comparison test to isolate the cause too.

On the OTHER hand...

... if the pressure has dropped at ALL fixtures, whether served by softener or not, then the fault may lie in your Pressure Reducing Valve (possibly underground) located near your meter.

The good news is the PRV is almost always the responsibility of the city/water supplier to service/replace. You may have to bug them a bit. ;')

RE: Pipes 'hum' when toilet is flushed and water pressure is low

Mine ended up being the whole house water filter. DIdn't think if was that because I had just changed it on the 1st of the month and today is the 17th... but once I removed it, it was filled with about a 16th of gunk and rust on filter... once I replaced it, I had no more issues of low pressure when flushing my toilets.. I am amazed of how quickly that filter got so bad...thank you for the suggestion.

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Plumbing Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here