Fixing a running toilet without a flapper often involves replacing the canister seal or adjusting the fill valve. This guide provides step-by-step instructions to diagnose and resolve the issue, saving water and money.

Understanding Flapperless Toilets

Before diving into fixes, understand that flapperless toilets commonly use a canister flush valve or a seal-based flush valve. Both rely on a tight seal to prevent leaks.

Diagnosing the Leak

Pinpoint the source of the leak:

  • Water trickling into the bowl after flushing: Likely a faulty canister seal.
  • Constant water flow and running fill valve: The fill valve is likely malfunctioning.
  • Loose flush lever: Check the chain or cable for tightness.

Fixing the Running Toilet

Safety First: Turn off the water supply to the toilet before starting repairs.

1. Addressing a Faulty Canister Seal

This is a common issue:

  • Turn off the water supply.
  • Flush the toilet to empty the tank.
  • Detach the chain or cable from the canister.
  • Remove the canister: Twist a quarter-turn counterclockwise and lift. Consult your toilet’s manual if needed.
  • Inspect the seal: Look for cracks, wear, or debris.
  • Clean the seal and seating surface: Wipe with a cloth or sponge to remove deposits.
  • Replace the seal: If cleaning fails, replace the seal (or the entire canister assembly).
  • Reinstall the canister: Twist clockwise to secure.
  • Reattach the chain or cable, with a slight slack.
  • Turn the water supply back on.
  • Observe: Check if the running has stopped.

2. Adjusting or Replacing the Fill Valve

If the fill valve is the problem:

  • Turn off the water supply.
  • Check the water level: It should be 1 inch below the overflow tube. If higher, the fill valve isn’t shutting off.
  • Adjust the fill valve: Use the adjustment mechanism (screw or clip) to lower the water level.
  • Clean the fill valve: Remove mineral deposits or debris. Disassemble if needed, following the manufacturer’s instructions.
  • Replace the fill valve: If adjustment and cleaning fail, replace it with a universal or model-specific valve. Follow the installation instructions.

3. Addressing a Tight Chain or Cable

This is a simple fix:

  • (Optional) Turn off the water supply.
  • Locate the chain or cable.
  • Adjust the length: Add a link or loosen the cable to create slack, allowing the canister to seat fully.
  • Test the flush: Ensure the canister seats correctly after each flush.

When to Call a Plumber

Consider calling a plumber if:

  • You’re uncomfortable with plumbing work.
  • The toilet continues to run after attempting the fixes.
  • The problem seems complex.
  • You notice damage beyond the seal or fill valve.