How To Install A New Toilet

New Toilet

Did you know you can install a completely new toilet in under an hour? Now, I know what you’re thinking: “Toilets must be extremely cumbersome to remove and replace!” That is simply not the case! Toilets are secured in place via two nuts and bolts and a single water line. That’s it!

To install a new toilet, you must first measure the existing toilet to ensure the new one will fit in the required space. Remove the old toilet by shutting off the water supply and draining the bowl and tank, disconnecting the water supply and removing the bolts holding it to the floor, and cleaning out the old wax ring. Inspect the flange to ensure there are no cracks or leaks before setting a new wax ring, placing the toilet, and leveling. Finally, install the new toilet seat, connect the water supply, turn on the water, and caulk around the base of the toilet.

Whether you’re upgrading your toilet in favor of a more efficient unit, putting in a high volume toilet to reduce clogging, or simply want to update a dated one, installing a new toilet is a simple process as long as you have the right knowledge for the job. Continue reading for a step-by-step guide on how you can install a new toilet and save money on the cost of labor.

Measure the Existing Toilet

Measure the existing toilet prior to removing it so as to not purchase a new one only to realize it doesn’t fit. The main measurements to pay attention to are from the securing bolts to the nearest obstacle in each direction.

To take these measurements, pop off the bolt cover caps, which are the little white dome caps on either side of the toilet at its base. These small pieces of plastic are what hide the only two areas of where the toilet is secured to the floor (crazy, right?).

Measure from the bolts to the nearest obstacle, which is typically either the back wall, a cabinet or vanity, or a bathtub or shower insert. Compare these measurements to the specs of the new toilet you intend to purchase and ensure adequate clearance. The standard distance from back wall to bolts is 12″.

Remove the Existing Toilet

We’ll start off by getting the old toilet out of the way. If you did not remove the bolt cover caps when you measured, now is the time to do so. Before we begin, it might be a good idea to put a pair of rubber gloves on.

Shut Off and Disconnect Water Supply

Before you can remove the old toilet, you’ll need to shut off and disconnect the water supply. Find the water shutoff valve attached to a pipe protruding from the wall. Turn the water shutoff valve counter-clockwise until you hit the stop, being careful not to over-tighten.

You run the risk of sheering the valve itself or damaging the threading if you over-tighten, particularly in older units that have been exposed to years of erosion caused by water contact. Should this happen, you will need to replace the valve before continuing. Shut off the water to the entire house and replace the valve.

With the water turned off, disconnect the far end of the water line (the end that feeds into the toilet). It is a good idea to have a bucket or large cup handy for the water that is trapped in the line. Place the bucket under the line and turn the attaching nut clockwise until it can be removed by hand. Continue by hand until the line disconnects and turn the line upside down over the bucket.

Clear Out All Water in the Toilet

Start to empty the water in the toilet bowl and tank by flushing once or twice, dependent on the capacity of your tank. This should leave you with a small amount of water in the bottom of the tank and nothing in the bowl. Take a large shop sponge or some rags and soak up the remainder of the water in the tank.

Remove Old Toilet

The next step largely depends on whether or not you have an extra pair of hands to help. If you don’t, it is a good idea to disconnect the tank from the bowl to remove the toilet in two pieces. If you have two people, the toilet can be removed in one piece. To disconnect the tank from the bowl, find the two plastic lug nuts underneath the tank and remove them. The tank should now come off easily.

Remove the two nuts holding the toilet in place (the ones hidden by the plastic caps). Start with a wrench and finish by hand. Score any existing caulking around the base of the toilet with an exacto knife or box cutter to ensure the toilet will come up with ease.

With the nuts removed, gently rock the toilet back and forth to loosen the wax seal. The wax seal serves to hold the toilet in place while creating a water-tight seal with the flange. Now simply lift the toilet straight up over the bolts and set the unit out of the way.

Remove Existing Wax

You should see remnants of the wax seal left on the floor/flange. Take a metal putty knife and scrape off the old wax. With the bulk of the wax removed, clean the top of the flange with all purpose cleaner and some paper towels. This will allow the new wax seal to adhere as intended to the flange in addition to giving you an opportunity to inspect the existing flange.

Inspect the Flange

Now that the flange is clean, inspect the metal or PVC piece for any dings, cracks, or deformities. The number one cause for toilet leaks in a bathroom is a bent or cracked flange. It should look like a uniform and smooth circular piece of metal or PVC. If you find any deformation, you will need to replace the flange.

While inspecting the flange, take a look at the bolts as well. If either one appears eroded or looks like the threading is worn or bare, you will need to replace them with new bolts (that should come with your new toilet unit). If they clean up well and look nice, you can simply leave the flange and bolts from the old toilet in place and install the new toilet directly on the old pieces.

Install New Toilet

Let’s get this new toilet in! Unpack your new toilet and open up your wax seal, which will likely need to be purchased separately. Have either locking shims or wood shims ready to go for the leveling process.

Install New Flange and Bolts, if required

If your flange needs to be replaced, start by removing the attaching bolts. The flange itself should be secured to the subfloor with either three or four screws. Remove the screws and the flange should come straight out.

If you simply need to replace the attaching bolts, use an adjustable wrench to torque the bolts out counterclockwise and replace with the new bolts.

The installation of a new flange is straightforward and the exact opposite of the removal process. Simply set the unit in place and secure to the subfloor with three to four screws, depending on the design of the flange.

Install New Wax Ring

With the flange in place and the new toilet unpacked, attach the new wax ring to the toilet, not the flange! Trust me on this one, it is much easier to affix the wax seal to the toilet as opposed to the floor. It will create a much tighter seal which leads to a lower chance of a poor seal in later steps.

Place the Toilet, Level, and Secure

Again, if you have two people for the project, the entire toilet (bowl and tank) can be placed together. If you are working alone, it is a much better idea to install the toilet in two pieces.

Lift the toilet up over the attaching bolts and gently lower into place. You should notice that the toilet doesn’t approach the level of the floor, which is due to the wax seal! Just as we rocked the toilet back and forth to break the seal, we will rock the toilet as we set it in place.

Gently shift the toilet back and forth as you apply downward pressure to create the best seal. Place a level on the top of the toilet bowl to check for level. You should have a little play with the wax seal. If you need to support one end of the toilet bowl to bring the unit to level, insert either wood or locking shims.

Locking shims are simply two pieces of plastic with interlocking teeth that allow you to adjust the size of the shim. Lock them into the desired height and set under the needed side of the toilet bowl.

I highly recommend always using a minimum of two shims to support one side of the toilet bowl!

Take your time to ensure the toilet is level so you don’t have to undo a portion of your hard work to correct it later! A lot of the time, toilets are installed over tile in a bathroom, which is not always perfectly level. If you are struggling to get the toilet to rest level, continue rocking it back and forth to play with the wax seal a little bit.

With the toilet now level, hand tighten nuts onto the protruding bolts on either side of the toilet. Take a wrench and tighten one bolt at a time, being careful not to over-tighten.

A good rule of thumb is to tighten one a quarter-turn before going to the other nut. Continue this pattern until the toilet is secure, making sure it remains level as you go. Once secure, place the plastic bolt cover caps over the nuts and bolts.

Pro Tip: Do not over-tighten the attaching nuts! You run the risk of cracking the toilet if you do!

Finally, if you had to install the toilet in two pieces, place the tank onto the bowl and attach the two pieces together with the provided nuts.

Install New Toilet Seat

The toilet seat attaches just as easily as the toilet itself. You should see two holes near the back of the toilet bowl. The new toilet seat will have two plastic bolts attached to the underside that match the holes in the toilet bowl, and two plastic nuts or lug nuts.

Simply set the toilet seat in place through those two holes in the toilet bowl. From the underside of the toilet bowl, attach the nuts by hand before tightening with a wrench. Again, careful not to over-tighten!

With the nuts secure, take your wrench and torque the ends of the bolts perpendicular to the bolts themselves and they should shear right off, removing any excess bolt length.

Finishing Touches

Once the toilet is in place and secure, reconnect the water supply and turn the water back on by turning the valve clockwise until the stop. Make sure you use teflon tape to ensure there will be no leaks in the water supply line. Allow the tank to fill and flush the toilet two to three times to ensure there are no leaks.

The most common place to find a leak is underneath the toilet itself, which means the wax seal is not tight or you have a broken or cracked flange. It is highly important that you check for leaks prior to caulking around the base of toilet for this reason! If you find a leak in the water supply line, simply turn the water back off, disconnect the water supply line, and reconnect carefully using new teflon tape.

With no visible leaks, you can now caulk around the base of the toilet using a mold-resistant caulk. And that’s it! Now you can feel confident in installing a new toilet on your own without the need to hire a professional.

Luke Miller

Luke Miller is a writer, real estate professional, rental property investor, and home renovation enthusiast based in Phoenix, Arizona. He grew up in Iowa in a self-sufficient household where he learned the skills to do everything from plumbing, drywall, to basic handyman repair for everyday problems. He enjoys sharing his vast experience and his continuous learning with fellow DIY enthusiasts.

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