Toilet Occasionally Leaking or Running

Why is my toilet occasionally leaking or running? This troubleshooting document relates to one or two-piece toilets.

Description of issue: With this issue, toilets run or leak because water is leaking out of the tank. This may occur because the trip lever arm may be binding, water may be overflowing into the flush valve overflow tube or the flush valve flapper/canister seal may be worn.  

Symptoms of Occasional Leaking or Running: You will hear the toilet fill valve running occasionally to refill the toilet tank. Once the water drops low enough, the fill valve will turn on to refill the tank.

Corrective Actions:

1. Adjust the trip lever chain for proper slack . The chain should have roughly one to two links of slack at most so the excess chain does not get caught on the trip lever arm. Remove excess chain if needed. 
2. Adjust tank water level to prevent water from overfilling and running into the flush valve overflow (Fig. 1).
3. Replace worn or dirty flapper or canister seal.
   
   • There are two different types of flush valve styles (Fig. 1) that may wear down over time due to water conditions or from the use of in-tank cleaners. 
   • There is an additional flush valve gasket where the flush valve meets the bottom of the tank. It is recommended to replace the flush valve gasket to ensure leaking is resolved.
     • Replace a Canister Flapper Seal
     • Video - GP1059291 Canister Seal Replacement Kit for Single-Flush Toilets
     • Video - GP84995 Flapper Replacement for One-Piece Toilets

Fig. 1 Flapper style flush valve (left) and canister style flush valve (right).

The part number of the flapper or canister seal and the flush valve gasket will vary depending on the toilet model number.

Click here to identify your toilet model number and to locate parts to service your product.

Additional Resources

• If the toilet is not running occasionally, but seems to be running constantly without turning off, reference, "Toilet Constantly Leaking or Running" for further troubleshooting.
• If tank water spills into the overflow but eventually stops, the tank water level will need to be adjusted. Reference "Adjust the Amount of Water in a Toilet Tank."
• If tank water spills into the overflow but does not stop and keeps running, reference "Toilet Constantly Leaking or Running."
• Uncertain if the toilet is constantly or occasionally running? Do a water test to determine the issue. Test to Identify Leaking in a Toilet.
• Warranty Information
• Identify Your Product
• Toilet Parts Catalog