Asked on Dec 13, 2012

Toilet: Rumbling / Vibrating Noise when FILLING up (SMOOTH when flush)

Jim Ginas
by Jim Ginas
When flushing the toilet, no problem, smooth flush like all others, no issues. (My 1st inclination of the noise when filling up was a clogged toilet, but it flushes quickly and no problems.) **** Issue is when water is filling back up, a LOAD VIBRATING NOISE as the water fills up. fills up fine, but what causes the load vibration?
  12 answers
  • Nest Home Improvement Nest Home Improvement on Dec 13, 2012
    Hard thing to diagnose online but you may have a condition called 'water hammer'. Water hammer is air in your water line. A plumber can surely diagnose and there are things a plumber can do to correct this condition for you. Long-term you could have bigger problem on your hands as the vibration can loosen pipes and fittings and may cause leaks.
  • Jim Ginas Jim Ginas on Dec 13, 2012
    ok, thank you. so I understand a plumber can fix the air in the line. Can a home owner do anything to resolve this, that is simplistic so the long term problem does not occur?
  • Nest Home Improvement Nest Home Improvement on Dec 13, 2012
    I wouldn't suggest it. This really isn't a DIY project. Let a plumber handle it. I have heard from homeowners before "Wow the plumber came and fixed the problem in 5 minutes and it cost me $90!". My reply to that is typically, if you knew what the plumber knew and have done this similar task before 100's of times, had the correct tool and parts, then you could do it yourself in 5 minutes too. It is not easy to become a most states it takes schooling, year of apprenticing, passing an exam etc.
  • KMS Woodworks KMS Woodworks on Dec 13, 2012
    @Jim G water hammer is often due to "hydraulic" shock, as you may remember from your basic Physics classes that water is an "incompressible" fluid unlike air. I have seen this problem before an those cases it was not really water hammer but just a failing fill valve assembly in the toilet tank. That is a easy DIY fix. You can pick up replacement fill kits are your local home center. These are pretty generic. To swap it out close the supply valve then flush the toilet...this will remove most of the water from the tank. Next you will unscrew the supply hose from the tank. You can place a small bucket or bowl on a towel to catch any drips. Once the hose is off unscrew the nut at the bottom of the fill assembly and lift if out. Take note of the small hose that goes to the overflow pipe this is part of the assembly. re-install the new kit, attach the line and open the valve...pretso your back in business. An average handy Homeowner should be able to do this swap in about 10-15 min. no sense paying a plumber a min 1 hour trip charge at $60 or so.
  • Check your water pressure. If the pressure is to high or the flush valve is starting to to, it cannot hold the water back and the pressure causes the valve to vibrate until it is finely able to completely shut off. If the noise is continuous during the fill process the valve is not opening all the way when the float drops. Check to see that it is moving freely. Also mineral build up assuming hard water will prevent the valve from opening in some cases all the way resulting in this noise. So check pressure first, just in case the city raised it and you were not aware. Then check the motion of the valve float for movement. Then when flushing put your hand on the top of the valve and feel for vibration, If it is still occurring, then replace the flush valve. They can be taken apart and cleaned, but be prepared to replace as this is not always successful.
  • I got to agree with Nest on the plumber aspect as it is hard to say exactly what the issue or best fix is. As for the cost - an electrician I know loves coming back with well the $245 was for knowing where to look & $5 was for the time to fix it One quick thing though you can check is the valve - is the valve open all the way? I had just replaced a vanity top once and all of a sudden this same type of issue popped up - well it wasn't a 1/4 turn valve it was the old style that took three turns to fully open - once I finished opening it, everything was good
  • Jim Ginas Jim Ginas on Dec 13, 2012
    interesting posts, thanks all. After I initially posted, I did a search on water in the lines and ran around and tried an online post fix for clearing air out. (turn all faucets on half way to get air out. - didn't work!) ** ONE thing to note: ONLY ONE TOILET does this and nowhere else in the house (5 bathrooms) or any other faucet does this occur. ** ASSUME this really helps to determine maybe it is the one toilet issue and probably the fill valve assembly as KMS/Colorado suggests. I imagine this is a fast and easy fix to try and at the very least, if that doesn't resolve it, we have a new assembly that should last a few years. I'll try that first, and also check per Woodbridge. All else fails, I'll call American Home Shield for a plumber to check it out and that cost is only $60 to us. Thanks again for the help!
  • KMS Woodworks KMS Woodworks on Dec 13, 2012
    let us know how it works out
  • Jim Ginas Jim Ginas on Dec 13, 2012
    will do..... do you agree that with the rattling ONLY happening when the one toilet is flushed, and doesn't happen on any other faucets, shower or toilet, it probably isn;t air in the line? Just the toilet fill valve?
  • KMS Woodworks KMS Woodworks on Dec 14, 2012
    If the problem is isolated then yes it is probably is a faulty fill valve.
  • Jimmy R Jimmy R on Apr 16, 2016
    We had this happening when the toilet would refill , What I found that helped was , Turn off the water outside , flush the toilet , open every faucet in the house cold an hot , Then turn the water back on , an let the Toilet fill , after it fills start turning off the faucets one by one , The ones lowest to the floor first , What your doing is forcing / bleeding any air outta the system , it took 3 times to do this by the way , Also if there is any sediment trapped in the flush valve it would cause the noise as well, which I checked first ,,
  • Jim Ginas Jim Ginas on Sep 01, 2018

    I assume changing the Fill Valve assembly fixed it. ** NO issues since. Much thanks!