The good news is that when your toilet makes noises after flushing, the cause is usually easy to diagnose. Toilets are simple devices with very few parts, so most homeowners can fix their own toilets and stop those noises for good.
Toilet Hisses for a Long Time After Flushing
After you push the toilet lever, you may hear a hissing sound, like water running. While this is the normal sound of the toilet refilling its tank, the sound continues for longer than the expected one to three minutes. The seal in the toilet fill valve might be corroded or deteriorated. The seal can be cleaned or replaced. If this does not fix it, replace the entire toilet fill valve.
How to Fix It
Toilet Squeals or Whistles After Flushing
After you flush the toilet, the toilet makes a high-pitched whistling or squealing sound. The sound is brief and it ends when the water is finished filling the tank. In most cases, a dirty or bad toilet fill valve seal is the cause of a squealing or whistling toilet. Cleaning the valve seal or replacing it entirely usually will cure the whistling sound.
How to Fix It
Toilet Makes a Flushing Sound on Its Own (Ghost Flush)
Long after you flush the toilet, the toilet makes a flushing sound all on its own. Your toilet is either partially or completely flushing on its own, independent of you pressing the lever. This toilet sound is often called a ghost flush or phantom flush because it sounds eerily like someone flushing the toilet, even though no one is in the room. You may need to adjust the refill tube that attaches to the overflow pipe or you may need to replace the toilet flapper.
How to Fix It
If readjusting the refill tube does not work, replace the toilet flapper with a toilet flush valve repair kit.
Toilet Bangs or Hammers After Flushing
After you flush the toilet, the toilet makes a loud bang, thump, or hammer sound. The sound occurs after the toilet tank has finished filling up. This toilet hammering sound is sometimes heard in other fixtures and appliances, especially washers. Quickly cutting off the flow of water causes water supply pipes to bang within the house—against studs, joists, and beams. Water hammer can be easily fixed by installing a mini in-line single fixture water hammer arrester.
How to Fix It
Toilet Moans or Makes Horn Noise After Flushing
After you flush the toilet, the toilet makes a loud horn-like, moaning, or foghorn sound. The toilet may also sound like it is humming or vibrating. The sound is brief, but it happens nearly every time you flush the toilet. When the water supply valve to the toilet is partially closed, this can create a vibration that results in a horn-like or moaning sound.
How to Fix It
If that fix does not stop the toilet from moaning, replace the toilet’s water supply valve.
Toilet Makes a Bubbling or Gurgling Sound After Flushing
After you flush the toilet, the toilet makes a deep gurgling or bubbling sound. The sound appears to be coming from the toilet base or bowl. The toilet might be partially blocked, the refill tube may have come loose, or a vent stack might be blocked.
