Toilets are the most common source of household leaks. In many cases, a toilet leak is silent, making it difficult to spot. These leaks can range in size from less than a gallon per hour to multiple gallons per hour. Often a toilet leak can be repaired with inexpensive parts.

Cause of Toilet Leaks
Over time, the toilet flushing mechanisms can decay and cause leaks. Typically the fill valve and the flapper need to be replaced due to wear and tear. The most common causes of leaking toilets are:

  • Leaking flapper - The flapper is worn or warped, preventing a tight seal. Drop a dye tablet or several drops of food coloring into the tank and wait an hour. If the colored water appears in the bowl before flushing, the toilet flapper is leaking and needs to be replaced. 
    • The fix: Disconnect the old flapper and install a new one. Flappers do not last forever so check on them periodically.
  • Running toilet - Do you jiggle the handle to keep the toilet from running? If yes, the flush lever and chain, or the handle itself may be sticking.
    • The fix: Adjust the nut that secures the flush level inside the toilet tank. If that does not help, you may need to replace the handle.
  • Leaking fill valve - Remove the toilet lid from the tank and mark the water level with a pencil. Flush the toilet. The water level should return to the marked line when the tank refills.
    • The fix: If the tank's water level is above or below the pencil line, adjust the water level in the tank so the water shuts off 1-inch below the overflow tube.
  • Loose handle - If the handle feels loose every time you flush the toilet, the nut inside the tank may be loose, which is easy to fix!
    • The fix: Remove the lid and tighten the nut so that it is tight but still moves freely.

Detect a Toilet Leak

  1. Carefully remove the toilet tank lid
  2. Drop food coloring or dye tablets into the water of your toilet's tank
  3. Wait one (1) hour and do not flush during this time.
  4. If the dye color appears in your toilet bowl, you have a flapper leak and need to fix it.
  5. The dye water in your tank will be removed during your next toilet flush.