Down and Dirty Toilet Replacement

Toilet bowl upside-down with wax ring.

Step #6: Install Toilet Bowl

Now comes the fun part—installing your new toilet!

How to install a toilet bowl:

  • Test Fit Toilet Bowl: Position the new toilet bowl over the toilet flange to make sure it fits on the floor without rocking. Remove the bowl and turn it upside-down on the floor, using a towel or foam pad for padding.
  • Install Toilet Flange Bolts: It’s a good idea to replace the toilet flange closet bolts, even if the old ones are still usable. Slide the old bolts out of the slots in the flange, and slip the heads of the new ones in so the bolts are parallel to the wall behind the toilet.
  • Position Wax Ring: Place the new wax ring on the drain opening in the bottom of the bowl with the rubber gasket facing away from the toilet bowl.
  • Remove Toilet Drain Cover: Remove the drain cover used to keep sewer gases from coming out of the drain pipe.
  • Caulk Toilet Bowl Base: If desired apply a bead of caulking or sealant around the base of the toilet bowl to seal it to the floor. You can also seal around it after the bowl is in place, or not caulk it at all. Since caulking the bowl can be messy, I prefer not to seal it unless there’s a gap between the floor and bowl.

Toilet flange bolt with washer and nut installed.

  • Seat Toilet Bowl: Turn the toilet bowl over, position the bowl so it’s centered over the toilet flange, and press the toilet bowl down firmly. You may need to slightly twist or rock the bowl back and forth to flatten out the wax ring until the bowl contacts the floor. Position the bowl so it’s perpendicular to the wall behind it.
  • Attach Flange Bolt Nuts: Place the washers that came with the closet bolts on the toilet bowl base. Hand tighten the nuts on the bolts, then use a deep socket or wrench to tighten up the bolts evenly from each side. DO NOT OVER TIGHTEN the nuts, as this can cause the base of the toilet bowl to crack!
  • Level Toilet Bowl: Place a level on the top rim of the toilet bowl and check to be sure the bowl is level in all directions. Adjust the tightness of the nuts and/or insert thin shims under the bottom of the bowl until the toilet bowl is level.

Leveling toilet bowl.

  • Cut Closet Bolts: If needed to install the bolt caps, use a hacksaw to cut the closet bolts off above the nuts, being careful not to damage the bowl with the saw.
  • Install Closet Bolt Caps: Place caps over the ends of the closet bolts. Some closet bolt caps snap in place on the washer, or you can fill the cap with plumber’s putty and press it into the bolt.

Using screwdriver to tighten bolt on toilet tank.

Step #7: Install Toilet Tank

Some toilet tanks and bowl come as one piece, but many have a separate tank that attaches to the bowl with bolts and a rubber gasket.

How to install a toilet tank:

  • Install Rubber Toilet Tank Gasket: Turn the toilet tank upside down on a towel or foam pad, and slide the rubber gasket over the outlet on the bottom of the tank with the tapered side of the gasket facing away from the tank.
  • Install Toilet Tank Bolts: Turn the toilet tank over, slide the rubber washers on the toilet tank bolts, and insert the bolts into the holes in the bottom of the tank from the inside.
  • Position Toilet Tank: Carefully place the toilet tank on the bowl with the bolts through the holes in the top of the bowl. Check to make sure the tank is parallel to the wall.
  • Attach Toilet Tank Nuts: Insert the metal washers on each tank bolt from underneath the bowl, followed by the tank bolt nuts. Hand tighten the nuts to hold the tank loosely in place. Place a socket or wrench on the nut and a screwdriver inside the tank to keep the bolt from spinning. Tighten the two nuts up evenly with the wrench until the tank is firmly seated on the bowl. DO NOT OVER TIGHTEN the nuts, as this can crack the tank or bowl!
  • Attach Water Supply Line: Attach the supply line to the shutoff valve (if you’re replacing it) and the bottom of the toilet tank. Tighten the fittings using an open end or adjustable wrench.

Using screwdriver to tighten bolts on toilet seat.

Step #8: Install Toilet Seat

While some toilets come with a seat, many do not. Make sure the seat you buy is made to fit the shape of the toilet bowl.

How to install a toilet seat:

  • Position Toilet Seat: Place the toilet seat on the bowl, and insert the seat bolts through the holes in the seat and toilet bowl.
  • Attach Toilet Seat Bolts: Screw the nuts on the seat bolts and tighten until the seat is snug.

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:

  • 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.
  • 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.
  • 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.
  • 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.
  • 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.
  • 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.


Please enter your comment!
Please enter your name here