How To Install A New Toilet

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Modern toilet bowl near white wall in bathroom

Skill Level: Intermediate

Time: 2-4 hours

Cost: $100+ (depends on the model of the toilet)


  • Work gloves
  • Safety Glasses
  • 2-foot level (or longer)
  • Hack Saw
  • Putty Knife
  • Tongue-and-groove pliers
  • Adjustable wrench
  • Large sponge
  • Old towels
  • Bucket
  • Utility knife


  • New toilet
  • Wax or foam ring
  • Silicone caulk (optional)
  • PVC primer (optional)
  • PVC cement (optional)

How To Install A New Toilet

Are you looking to upgrade your bathroom with some luxurious bathroom remodel ideas?

Or are you just trying to install a new toilet? Are you wondering how to begin? This guide will give you all the steps and tips needed on how to install a new toilet, from turning off the water supply on your old toilet to setting your new toilet bowl on the flange.

And if you’re looking for other ways to upgrade your bathroom, be sure to check out our blog post on 10 easy bathroom upgrades that make a big impact.

By the end of this guide, you will understand how to complete a new toilet installation by yourself. So grab your tools, and let’s get started! 

1. Turn Off The Water Supply On The Old Toilet

Residential toilet water shutoff valve next to wall

Before you install your new toilet, you’ll need to first work on removing your old toilet. 

Note: If you are installing a toilet in a place where there isn’t an old toilet, go ahead and skip to Step 9 of this guide.

The first step to installing a new toilet is to turn off the water supply on your old toilet. This is usually located behind the toilet or near the wall–just follow the pipe from the wall until you find it. Once you’ve located it, turn off the shut-off valve.

2. Flush And Remove the Remaining Water

After shutting off the water supply, flush the toilet until most of the water has been removed from the bowl. Use a large sponge to soak up the remaining water and squeeze it into a bucket. Repeat this process until you have removed all the remaining water from the toilet bowl.  

3. Disconnect Water Supply Line

man unscrews a drain tank of a toilet

Once all of the water has been removed from your old toilet, it’s time to disconnect the water supply line. This is usually connected with a nut and washer–simply unscrew this connection with an adjustable wrench and remove it from your old toilet.

4. Unscrew The Nuts On The Bottom Of The Tank (Not Required For One-Piece Toilets)

Note: If the old toilet you’re replacing is a one-piece toilet (so no detachable tank), you can skip to Step 6 of this guide.

For two-piece toilets, you will need to start by unscrewing the nuts on the bottom of the tank before you move on to the mounting bolts on the toilet bowl itself. On older toilets, these nuts may be rusty due to their constant exposure to moisture.

If you are unable to loosen the nuts, try applying WD-40 or a similar penetrant spray and waiting a few minutes before trying to loosen them again. If that doesn’t work, use a hacksaw to cut the bolts.

5. Lift Tank Off Of The Bowl (Not Required For One-Piece Toilets)

Once the nuts holding the tank have been loosened and removed, carefully lift the tank off of the bowl.

Don’t forget to wear your work gloves! Old tanks can crack, and broken ceramic (or porcelain) can be sharp. Set the tank on an old towel.

6. Remove Mounting Nuts From Bowl

After removing the detachable tank (if your toilet model has one), it’s time to remove any mounting nuts from the bowl.

You’ll find the mounting nuts located at the base of the toilet, where they secure the toilet bowl to the floor.

Remove the plastic caps that cover the mounting nuts (you may need to pop them off with a flathead screwdriver).

To loosen the mounting nuts (also known as closet bolts), carefully turn them counterclockwise using an adjustable wrench. If the mounting bolts are too corroded to be taken out this way, you may need to use a hacksaw to cut them instead. If you do have to cut them loose, you’ll need to buy new mounting hardware to secure your new toilet to the floor.

7. Lift Bowl Off The Floor

Note: You should have an assistant help you with this step because some toilet bowls can be quite heavy!

Carefully lift the bowl off the floor and set it on its side on an old towel.

8. Remove Old Wax Ring

Plumber showing wax ring on toilet

Note: If your old toilet used a foam gasket instead of a wax ring, you might be able to reuse it. Just verify the foam is in good condition and save it for your new replacement toilet.

Unlike foam gaskets, wax rings can’t be reused, so you’ll need to scrape off any remnants of the old wax ring on the toilet flange on the floor with a putty knife before you place the new wax ring.

Pro tip: We recommend scraping the wax off the base of the old toilet just to ensure it doesn’t fall off anywhere in your house when you are disposing of the old toilet.

9. Inspect The Toilet Flange (New Toilet Installation Starts Here)

Before you install your new toilet, you’ll need to verify the toilet flange is in good condition. If it is damaged, you will need to replace it.

Pro tip: If you do need to replace the flange, take a picture of it with your phone to ensure you get the same type when you go to the hardware store.

If the flange is undamaged, you can keep it in place for your new toilet installation. Just stuff an old rag in the soil pipe to block sewer gas and prevent anything from accidentally falling in.

If you are installing a toilet in a new bathroom that never had a toilet before, there might not be a flange, so you may need to install the flange yourself. Follow the instructions below to attach a new flange:

  • Apply PVC primer to the outside edge of the soil pipe and the inside edge of the flange pipe extension.
  • Next, apply PVC cement to the same locations on the soil pipe and flange pipe.
  • Push the flange pipe onto the soil pipe until the flange is level with the floor.
  • Secure the flange to the floor with stainless steel screws (typically included with new toilet flange kits).

10. Test Set The New Toilet Bowl On Flange To Verify The Fit

With the help of an assistant, set your new toilet bowl on the flange to ensure it fits correctly. Make sure the bolts that attach the toilet to the floor align with the holes on the base of the toilet.

You should also take this opportunity to verify that your new toilet is level. Place a level that is at least 2 feet long across the toilet bowl to see if it sits flush on the floor.

If it’s not level, insert toilet shims under the toilet until it is level. Any excess toilet shims that protrude past the edge of the toilet can be trimmed with a utility knife after installation is complete.

After verifying the toilet fits and is level, lift it off the flange and carefully set the toilet bowl upside down (or on its side) on an old towel.

11. Place New Wax Ring

Note: Some toilets use foam gaskets instead of a wax ring. The same general process applies to both. The main difference is that a foam gasket holds its shape better, so it can be reused, unlike a wax ring.

Once you’ve verified that everything fits properly, apply a fresh wax ring on top of the toilet outlet (or horn) found on the bottom of the toilet. This wax ring creates an airtight seal when you fit your new toilet bowl onto it. Make sure to press down gently but firmly on the wax ring to ensure that it’s secured properly. 

Once a wax ring is pressed on a flange, it can’t be reused. If you have to remove the toilet after setting it onto the flange, you’ll need to get a new wax ring!

12. Set New Toilet Bowl 

Carefully set your new bowl on top of the flange, making sure that all four bolts line up with their respective holes in the bottom of the bowl. As you do this, be careful not to move or dislodge the wax ring–if you do, start over again with a new one!

Once everything is lined up correctly, gently press down on either side of the bowl until it’s firmly seated on top of the toilet flange.  

13. Carefully Tighten Mounting Nuts

Using an adjustable wrench or socket set (depending on what type of mounting nuts came with your toilet installation kit), carefully tighten each mounting nut until they’re securely fastened around each bolt under the base of your toilet bowl.

Be careful not to overtighten them, as this could cause damage to both your toilet and flooring. It’s surprisingly easy to crack the toilet base by overtightening the mounting bolts.

Just make sure they’re tight enough so that there’s no wobble when you sit down or stand up from your new toilet. After the bolts are snug, place the plastic caps over them. If your bolts are too long to cover with the caps, you may need to trim the excess bolt length with a hacksaw.

Pro tip: Try alternating between tightening each mounting bolt to help keep the toilet level.

14. Attach The Tank (Not Required For One-Piece Toilets)

man working with toilet tank in bathroom

If you have a two-piece toilet, you’ll need to attach its tank to its base using the bolts included with your new toilet. (If you are installing a one-piece toilet, you can skip this step.)

Most new toilets today will already have the flush valve assembly installed in the tank. If not, follow the manufacturer’s instructions for setting up the flush valve assembly in your specific model of toilet.

Two-piece toilets typically already have the rubber gasket installed on the bottom of the tank where it sits on the toilet. If your toilet model doesn’t already have the gasket attached, simply place the rubber gasket over the tank outlet. Then insert the bolts and washers that will secure the tank to the toilet through the appropriate holes.

With the help of an assistant, carefully set the tank onto the toilet, making sure that the bolts are inserted into the appropriate holes on the toilet. Then carefully tighten the nuts, alternating between each bolt to keep the pressure even. After all attachment bolts are securely fastened, reconfirm that the tank is level.

15. Attach Toilet Seat And Lid

Now comes the time for one of our favorite steps–attaching a brand-new lid and seat combo! Whether you opted for a standard plastic model or something more luxurious like wood, just make sure all hardware is tightened securely before moving on.

16. Reconnect Water Supply Line

Reconnect the water supply line to the toilet tank, following the same procedure you used when disconnecting it. Start with tightening by hand, then carefully tighten some more with pliers.

17. Turn On Water Supply Valve

Turn the water supply valve back on slowly until water begins flowing freely into the tank. You can check for any leaks around the water supply connections while you wait for the tank to fill up.

18. Flush And Check For Leaks

Person flushing toilet

After the tank has been filled, flush the newly installed toilet system several times while checking for any possible leaks. Alternate what connections you observe with each flush. Besides the water supply connections, you should keep an eye on the base of the toilet, as well as the area where the toilet and tank meet.

Note: Some toilet installers apply silicone caulk around the base of the toilet to ensure a seamless appearance for aesthetic reasons. However, some professionals recommend against this practice since it can make it more difficult to detect leaks and can lead to hidden water damage.

If everything appears fine after multiple flushes, then congratulations–you have successfully installed a new toilet!

Upgrade Your Bathroom With Home Pride Construction

With these simple steps in hand, installing a new toilet should no longer be intimidating! Just make sure that all the steps are followed correctly while still following any manufacturer’s specific instructions.

Now that you’ve successfully installed a new toilet, you may be thinking about other upgrades for your bathroom. If you’re ready to start a professional bathroom remodeling project, Home Pride Construction can help! Just give us a call or fill out our contact form today to get started.