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Quick answer
Turn off the water supply to the toilet and check the dual flush mechanism for blockages or misalignment. Adjust or replace the flapper, float, or fill valve as needed to stop the continuous running.
Confirm the symptom
- Toilet continuously runs after flushing
- Dual flush handle or buttons feel loose or unresponsive
- Water level in the tank is too high or too low
- Toilet makes gurgling or hissing sounds after flushing
- Water is visible leaking from the tank into the bowl
Tools and prep
- Adjustable wrench
- Screwdrivers (flathead and Phillips)
- Bucket or towel
- Replacement flapper or fill valve (if needed)
- Plumber's putty or sealant (if needed)
- Turn off the water supply to the toilet
- Allow the tank to empty completely before starting
Step-by-step troubleshooting
- Turn Off Water SupplyDo: Locate the water shut-off valve near the base of the toilet and turn it clockwise to shut off the water supply.Observe: Water flow to the tank stops.Means: The tank can now be safely worked on without water entering.Next: Drain the tank by flushing the toilet and using a sponge or towel to remove any remaining water.
- Inspect Dual Flush MechanismDo: Remove the tank lid and inspect the dual flush mechanism for any visible blockages, misalignment, or wear.Observe: Parts may be clogged with mineral deposits or not aligning properly.Means: A clogged or misaligned mechanism can prevent the toilet from sealing properly.Next: Clean or adjust the mechanism as needed.
- Check Flapper and ChainDo: Inspect the flapper for wear or damage and ensure the chain is properly connected and not too tight or too loose.Observe: Flapper may be cracked, warped, or not sealing properly.Means: A faulty flapper can cause water to continuously flow into the bowl.Next: Replace the flapper if damaged or adjust the chain length.
- Adjust Float LevelDo: Check the float's position and adjust it so that the water level is about 1 inch below the overflow tube.Observe: Water level is either too high or too low.Means: An incorrect water level can cause the toilet to run continuously.Next: Adjust the float as needed and test the toilet.
- Test the Fill ValveDo: Turn the water supply back on and observe the fill valve for any leaks or irregularities.Observe: Fill valve may be leaking or not shutting off properly.Means: A faulty fill valve can cause the toilet to run continuously.Next: Replace the fill valve if necessary.
- Test the ToiletDo: Flush the toilet using both the full and half flush options and observe if the running stops.Observe: Toilet should stop running after flushing and maintain a consistent water level.Means: The issue has been resolved and the toilet is functioning properly.Next: If the running continues, consider replacing the entire dual flush mechanism or consult a professional plumber.
Common causes
| Cause | Likelihood | Difficulty | Part often needed |
|---|---|---|---|
| Clogged or misaligned dual flush mechanism Mineral deposits or debris can block the mechanism, preventing it from sealing properly. | Common | Easy | Dual flush mechanism cleaning kit |
| Worn or damaged flapper A flapper that is cracked or warped can allow water to continuously flow into the bowl. | Common | Easy | Replacement flapper |
| Incorrect float level If the float is set too high, water can overflow into the bowl, causing the toilet to run. | Sometimes | Easy | Float adjustment tool |
| Faulty fill valve A fill valve that is not shutting off properly can cause the toilet to run continuously. | Sometimes | Medium | Replacement fill valve |
| Loose or improperly connected chain A chain that is too tight or too loose can prevent the flapper from sealing properly. | Sometimes | Easy | Adjustable chain |
| Worn or damaged dual flush handle/buttons If the handle or buttons are worn or damaged, they may not activate the flush mechanism correctly. | Rare | Medium | Replacement dual flush handle/buttons |
| Leaking tank to bowl seal A worn or damaged wax ring can cause water to leak from the tank into the bowl. | Rare | Hard | Wax ring |
Parts matching
Replace worn or damaged parts with compatible components to restore proper function.
- Flapper: Choose a flapper that matches the size and type of your toilet's flush valve.
- Fill valve: Select a fill valve that is compatible with your toilet model and water pressure.
- Float: Use a float that is designed for your toilet's specific mechanism.
- Dual flush mechanism: Ensure the replacement mechanism is compatible with your toilet model.
- Chain: Use an adjustable chain that allows for proper flapper operation.
Check the manufacturer's website for recommended replacement parts and compatibility information.
When to call a professional
- The toilet continues to run after replacing all visible parts
- You notice significant water leakage from the tank or base of the toilet
- The dual flush mechanism is completely non-functional or damaged beyond repair
- You are unsure about the correct replacement parts for your specific toilet model
- The issue persists despite following all troubleshooting steps
FAQ
Why is my dual flush toilet running even after I adjusted the float?
If the float is adjusted but the toilet still runs, the fill valve may be faulty and need replacement.
Can I use a regular toilet flapper on a dual flush toilet?
It is not recommended to use a regular flapper on a dual flush toilet as it may not provide the correct seal or function properly.
How do I know if my dual flush mechanism needs to be replaced?
If the mechanism is clogged beyond cleaning, damaged, or not functioning properly, it may need to be replaced with a compatible model.
What should I do if the water level in the tank is too high?
Adjust the float to lower the water level so it is about 1 inch below the overflow tube.
Is it normal for a dual flush toilet to make gurgling sounds after flushing?
Some gurgling is normal, but if it is excessive or accompanied by running water, it may indicate a blockage or faulty mechanism.