If you are hearing a vibrating noise after you flush your toilet, the problem may likely be the diaphragm inside the Fill Valve in your toilet tank. It’s a common problem and one that can be easily corrected.

When you flush your toilet, water goes into the Fill Valve from the bottom and travels through the Fill Tube and the tank then gradually begins to fill up with water and raises a float attached to the Fill Valve. Once the float reaches the top, it pushes down on a diaphragm inside the Fill Valve which stops the water. The tank is now refilled with water.

This diaphragm can wear out over time and as a result, when the water hits it, the diaphragm just ends up bouncing around the valve and creating those vibrations that you are hearing.

You may think that the answer then is to simply replace the diaphragm, but actually, it’s more cost effective to replace the entire Fill Valve. They are inexpensive and you’ll avoid any further problems with parts going bad on an old valve.

Why Do My Pipes Vibrate After Flushing The Toilet?

Vibrating pipes are usually a sign of a problem that causes a “water hammer” effect.

The term “water hammer” in a toilet refers to the noise and/or vibration that is produced when running water hits a closed valve – that is supposed to be an open valve. When the water hits that closure, and essentially has nowhere to go it creates a loud thud and/or vibration. It could also be caused by washers that are worn or damaged.

Water hammers should not be ignored because in time, they could cause some serious damage to your water pipes.

The best way to fix this problem is to install (and or repair) a water hammer arrestor. This usually looks like a pipe that is located close to a fixture. Your plumber can help you locate it, fix it and/or install one for you.

How Do You Stop Water Hammer When Flushing The Toilet?

There are 10 steps to take to try to fix the water hammer effect after flushing your toilet.

  1. Turn off the main water supply to the house.
  2. Turn on all your cold water faucets, starting with the faucets at the highest level of the house (2nd or 3rd floor). Do not turn them off.
  3. Let all the water drain from your faucets.
  4. Flush all the toilets in your house.
  5. Wait 30 minutes.
  6. Turn the main water supply back on.
  7. Wait 10 minutes to allow all the faucets to start running again.
  8. Turn off all these cold water faucets starting with the lowest level of the house (main floor or basement).
  9. Your toilets should automatically refill.
  10. Once all the faucets are turned off – flush all your toilets again. Listen for the water hammer effect.

If you follow this process and still feel the vibration or hear the loud knocking that the hammer effect creates, we recommend you call in a professional plumber to assess the problem.


If you have any questions about your toilets, call Atlantis Plumbing today at 770-505-8570. We are available 24 hours a day, 7 days a week.