Down and Dirty Toilet Replacement

Checking water supply line for leaks.

Step #9: Adjust Water Level and Check Toilet for Leaks

Now comes your moment of triumph (hopefully!) when you turn on the water to your new toilet and see if everything works as planned!

How to check a toilet for leaks:

  1. Turn on Water: Turn the water on at the shutoff valve (or water main if you’re toilet doesn’t have a shutoff valve), and allow the toilet tank to fill.
  2. Check Toilet Supply Line: Check the supply line at both the shutoff valve and toilet tank for leaks. If you find a leak, gradually tighten the supply line fitting until it stops.
  3. Check Toilet Tank Bolts: As the toilet tank fills up, feel under the tank and bowl to see if the tank bolts are leaking. If so, tighten up the bolts slightly until the leak stops.
  4. Check Toilet Tank Water Level: When the tank stops filling, check to make sure the water is at the designated level in the tank. If it’s not, adjust the float mechanism until it is.
  5. Check Toilet Tank/Bowl Seal: Flush the toilet and feel under the tank and bowl to make sure the rubber gasket between the tank and bowl isn’t leaking. If it is, tighten the toilet tank bolts slightly and flush again until it stops.
  6. Check Toilet Bowl/Flange Seal: Flush the toilet and check to make sure the seal between the bowl and floor flange isn’t leaking. If it is, tighten the closet bolt nuts slightly until it stops. If the flange/toilet seal still leaks, remove the toilet, replace the wax ring, and try again.

Printable To-Do List

Further Information


    • J.
      Try carefully tightening the toilet bolts that hold the toilet to the floor up, but don’t overdo it as it could crack the porcelain bowl. If that doesn’t help, put a shim between the floor and toilet.


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