If your toilet runs constantly but doesn’t have a flapper, the fix often involves adjusting or replacing parts of the fill valve or the flush valve assembly (tank ball, canister, or dual-flush mechanism). Here’s how to diagnose and address common issues causing these types of toilets to run.

1. Identifying Your Toilet Type

Understanding your toilet’s flushing system is crucial for effective troubleshooting:

  • Tank Ball Toilet: An older system using a rubber ball on a chain to seal the flush valve.
  • Canister Flush Valve Toilet: Employs a cylindrical canister that lifts to release water; often more water-efficient.
  • Dual Flush Toilet: Features two buttons/levers for partial/full flushes; mechanisms vary.

2. General Troubleshooting Steps

Before system-specific fixes, try these common solutions:

  • Check the Chain/Lifting Mechanism:
    • Ensure the chain isn’t too tight (holding the valve open) or too loose (preventing a complete seal). Adjust the chain length.
    • For canister valves, ensure the lifting mechanism moves freely.
  • Examine the Fill Valve:
    • A faulty fill valve is a common cause. Check for debris or a malfunctioning float.
    • Shut off the water supply. Disconnect and flush the fill valve cap to remove sediment.
  • Adjust the Water Level:
    • The water level should be slightly below the overflow tube. Adjust the float to lower the water level.
  • Listen Carefully:
    • Pinpoint the leak’s location (flush valve, fill valve, or overflow tube) to narrow down the problem.

3. Specific Solutions Based on Toilet Type

A. Tank Ball Toilets

  • Worn-Out Tank Ball: Replace the ball if it’s deteriorated.
    • Shut off the water supply.
    • Disconnect the chain from the old tank ball.
    • Unscrew the old tank ball from the guide arm.
    • Screw in the new tank ball.
    • Reconnect the chain, ensuring the correct length.
  • Improper Seating: Clean the flush valve opening to ensure a tight seal.
  • Bent or Misaligned Guide Arm: Straighten or replace the guide arm to ensure proper ball seating.

B. Canister Flush Valve Toilets

  • Safety First: Turn off the water supply before beginning any repairs.
  • Dirty or Damaged Canister Seal: Clean or replace the seal.
    • Shut off the water supply.
    • Remove the canister (twist counterclockwise and lift).
    • Clean the rubber seal.
    • Replace the canister assembly if the seal is damaged (use the correct replacement part).
    • Reinstall the canister.
  • Debris Under the Canister: Clean the area beneath the canister thoroughly.
  • Fill Valve Issues: Consult online resources for troubleshooting tips specific to your fill valve model, paying attention to:
    • Float Adjustment: Adjust the float to lower the water level.
    • Diaphragm Issues: Replace a worn or cracked diaphragm if possible.

C. Dual Flush Toilets

  • Mechanism Issues: Inspect all parts for damage or wear.
  • Button/Lever Alignment: Ensure proper alignment and activation of the flushing mechanism.
  • Manufacturer-Specific Solutions: Consult the manufacturer’s documentation for specific troubleshooting guides.

4. When to Call a Plumber

Call a professional if:

  • You’re uncomfortable with plumbing repairs.
  • You’re dealing with a complex dual flush system.
  • You suspect issues with water supply lines or internal piping.