How to Fix a Toilet Leaking at the Base

Inspect the Toilet to Find the Source of the Leak

The first step is to inspect your toilet and determine where exactly the leak is coming from. There are a few common places a toilet can leak from the base:

  • Where the tank meets the bowl – This is one of the most common sources of toilet leaks. If the tank-to-bowl gasket is worn out or cracked, water will leak when you flush.
  • Where the toilet base meets the floor – If the wax ring seal has shifted or is damaged, water can leak out from under the base of the toilet. This allows water to get under the toilet.
  • Cracks in the toilet bowl or tank – Very rarely, cracks can develop in the porcelain of the toilet. This will lead to water leaking down the side of the bowl.

Take a close look at all of these areas on your toilet. Look for any water, stains, or mineral deposits that indicate leaking. Pinpoint the exact source of the leak before moving on.

Shut Off the Toilet’s Water Supply

Before doing any repairs, you need to shut off the water supply to the toilet. There should be a shut-off valve below the tank or behind the bowl. Turn this clockwise all the way to shut off the water.

Flushing the toilet to empty out the tank is also a good idea. This allows you to mop up any remaining water in the tank or bowl.

Replace the Tank-to-Bowl Gasket

If the leak is coming from between the tank and bowl, replacing the gasket should fix the issue. Here are the steps for this straightforward repair:

  • Remove the tank from the bowl by unscrewing the large nut connecting the two pieces. Set the tank aside and empty out any remaining water.
  • Check the existing rubber tank-to-bowl gasket for cracking or damage. Remove the old gasket.
  • Get a new gasket and plastic tank-to-bowl hardware kit from a hardware store. Apply a thin layer of plumber’s putty around the bottom of the tank.
  • Set the new gasket in place and re-attach the tank. Tighten down the hardware evenly and firmly.
  • Turn the water supply back on and allow the tank to fill. Check for any leaks between the tank and bowl. The new gasket should prevent further leaking.

Replace the Wax Ring Under the Toilet

If the leak is coming from the base of the toilet, a damaged wax ring is usually the culprit. Follow these steps to remove the toilet and replace the wax ring:

  • Turn off the water supply and flush the toilet. Use a sponge to soak up any water on the floor around the base.
  • Remove the nuts from the bolts holding the toilet to the floor. Lift the toilet off the bolts and set it aside.
  • Using a putty knife, scrape away the old wax ring from the bottom of the toilet and the floor flange. Completely remove all the old wax.
  • Get a new wax ring and apply it evenly around the floor flange. Make sure no gaps exist between the flange and ring.
  • Lower the toilet back in place over the bolts and new wax ring. Press down firmly to set it.
  • Re-attach the nuts and bolts. Alternate tightening them until snug.
  • Turn the water supply back on and check for leaks. Additional weight or shims may be needed to fully seal the new wax ring.

Replace a Leaking Toilet Bowl or Tank

For cracks in the porcelain of the toilet bowl or tank, replacement is the only option. Here’s how to do this:

  • Turn off water supply and empty the toilet as outlined above.
  • Remove the tank, wax ring, and bolts to separate the bowl from the base.
  • Install a new wax ring on the base flange. Lower the new toilet bowl onto the flange.
  • Re-attach the tank, supply line, and shut-off valve to the new toilet.
  • Seal any gaps between the toilet and floor with caulk.
  • Turn on the water and test for leaks.

Replacing the actual bowl or tank is more labor intensive but necessary if they are cracked and leaking. Take appropriate safety precautions when lifting a heavy porcelain toilet.

Common Questions and Answers About Toilets Leaking at the Base

What are signs my toilet is leaking at the base?

Signs include water on the bathroom floor around the toilet, dampness or stains on the base of the toilet, mineral deposits from leaking water, and higher than normal water bills.

What if tightening the tank-to-bowl bolts doesn’t stop the leak?

The gasket is likely faulty and needs to be replaced. Cracks in the tank or bowl would also cause persistent leaks.

Is a leaking wax ring an emergency?

Not necessarily an emergency, but it should be repaired promptly. The longer the leak persists, the more potential for water damage to the flooring and subfloor.

Can I fix the leak myself or do I need a plumber?

In most cases, this is a DIY job. Replacing a wax ring, gasket, or toilet tank don’t require extensive plumbing skills. Turn off the water first and follow instructions carefully.

What’s the difference between replacing a wax ring vs. gasket?

These seal leaks from two different places – the wax ring seals between the base of the toilet and floor, the gasket seals between the tank and bowl.

How long does replacing a leaking wax ring take?

This job can be completed by a DIYer in about 30-45 minutes after gathering the necessary supplies. Allow additional time if also replacing the toilet bowl or tank.


Stopping a toilet that is leaking at the base starts with identifying the exact location of the leak and the needed repair. Replacing a faulty gasket, wax seal, or cracked tank or bowl are common DIY fixes. Act promptly once you notice leaks to prevent water damage around the toilet. With the proper replacement parts and by turning off the water supply, this is a job an average homeowner can tackle.