What you need to do before you start
Replacing a toilet is a task most people can do with basic tools and a few hours. The work involves disconnecting the old toilet from the water supply and drain, removing it, and installing a new one in its place. You do not need a plumber's license, though some jurisdictions require a licensed plumber to do the final connection to the main drain line — check your local building code before you start.
Before you begin, turn off the water supply to the toilet. Look for a small valve on the wall or floor behind the toilet, usually near the base. Turn it clockwise until it stops. Flush the toilet to empty the tank and bowl, then use a sponge or towel to soak up any remaining water in the bowl and tank.
Gather your tools: an adjustable wrench, a flathead screwdriver, a putty knife, a bucket, towels, and a new wax ring (the seal between the toilet and the drain). You will also need the new toilet itself. Most hardware stores stock standard white porcelain toilets, but you can choose different colors, heights, or water-saving models if you prefer.
Key Takeaways
- Turn off the water supply valve behind the toilet and flush to empty the tank before you disconnect anything.
- Disconnect the water line from the tank, unbolt the toilet from the floor, and lift it straight up — it will be heavy and may leak, so have towels ready.
- Remove the old wax ring from the drain opening and scrape the flange clean, then install a new wax ring before setting the new toilet in place.
- Bolt the new toilet to the floor, reconnect the water line, and run water through the tank and bowl to check for leaks before you consider the job complete.
- If water leaks from under the toilet base or the tank does not fill, you may need to reseal the wax ring or tighten the bolts — do not ignore leaks, as they damage the subfloor.
Disconnecting the old toilet
Locate the water supply line — a thin tube that runs from the valve behind the toilet to the bottom of the tank. Use your adjustable wrench to loosen the nut where the line connects to the tank. Turn it counterclockwise until the line comes free. Water may drip, so hold a bucket underneath.
Look at the base of the toilet where it meets the floor. You will see two bolts, one on each side, usually covered by plastic caps. Pry off the caps with a flathead screwdriver. Use your wrench to loosen and remove both bolts. Once the bolts are out, rock the toilet gently side to side to break the seal between the wax ring and the flange (the ring-shaped fitting in the floor). Lift the toilet straight up and set it on its side on a towel. The toilet is heavy — usually 80 to 100 pounds — so get help if you need it.
Preparing the drain opening
With the old toilet removed, you will see the drain opening in the floor and the wax ring stuck to it. Use a putty knife to scrape away the old wax ring completely. Work carefully so you do not damage the flange itself. Once the wax is gone, wipe the flange clean with a dry cloth.
Look at the flange to make sure it is not cracked or broken. If it is damaged, you will need to replace it — this requires cutting into the floor and is a job best left to a plumber. If the flange looks sound, you are ready to install the new wax ring. Press the new wax ring firmly onto the flange, centering it over the drain opening. The ring should stick to the flange on its own.
Installing the new toilet
Carefully lower the new toilet over the drain opening, aligning the bolt holes in the base with the bolts sticking up from the flange. Lower it slowly and evenly. The toilet should sit flat on the wax ring with no rocking. If it rocks, lift it slightly and adjust the wax ring, then try again.
Once the toilet is seated, insert the bolts through the holes and hand-tighten the nuts. Do not over-tighten — tighten each bolt a little at a time, alternating between sides, until the toilet is snug and does not move. Over-tightening can crack the porcelain. Replace the plastic caps over the bolts.
Reconnect the water supply line to the bottom of the tank. Use your wrench to tighten the nut, turning it clockwise until it is snug. Do not over-tighten this connection either — you only need it tight enough that water does not leak out.
Testing for leaks and filling the tank
Turn the water supply valve back on by turning it counterclockwise. Water will flow into the tank. Listen for the tank to fill and the fill valve to shut off — this usually takes a minute or two. Once the tank is full, flush the toilet and watch the bowl drain and refill.
Check for leaks at three points: where the water line connects to the tank, where the tank connects to the bowl (if you have a two-piece toilet), and under the base of the toilet where it meets the floor. If you see water dripping or pooling, turn off the water supply immediately and tighten the connection or bolt that is leaking. If water is coming from under the base, the wax ring may not be sealed properly — you will need to remove the toilet and reset it.
What to do if something goes wrong
If the tank does not fill after you turn the water back on, the fill valve may be stuck or the water line may be kinked. Check that the water supply valve is fully open and that the line is not bent. If the valve is open and the line is straight, the fill valve inside the tank may need adjustment or replacement — this is a separate repair and not part of the basic installation.
If the toilet rocks or feels unstable after you have tightened the bolts, the wax ring may not be sealing properly. You will need to remove the toilet, scrape away the wax ring, and install a new one. This is frustrating but not difficult — the second time is usually faster than the first.
If water leaks from under the base after a few days or weeks, the wax ring has failed. This can happen if the toilet was not seated evenly or if the flange is not level. Again, you will need to remove the toilet and reseal it with a new wax ring. If leaks continue after you have resealed twice, the flange itself may be damaged or the floor may be uneven — at that point, a plumber can assess whether the flange needs replacement.
When to call a plumber
You can handle the basic removal and installation yourself, but some situations call for professional help. If your local building code requires a licensed plumber to connect the toilet to the main drain line, you will need to hire one for that final step. If the flange is cracked or broken, a plumber can replace it. If the floor around the toilet is soft or rotted — a sign of long-term water damage — a plumber can assess the damage and recommend repairs.
If you have tried to reseal the wax ring twice and water still leaks from under the base, or if the toilet continues to rock after you have tightened the bolts, call a plumber to diagnose the problem. Persistent leaks damage the subfloor and can lead to mold and structural damage if left unaddressed.
Frequently Asked Questions
Do I need a new wax ring every time I remove a toilet?
Yes. The wax ring compresses when the toilet sits on it, and once it is removed, it cannot seal properly again. Always install a new wax ring when you reinstall a toilet. Wax rings cost a few dollars and are available at any hardware store.
Can I use caulk instead of a wax ring?
No. Caulk does not create a watertight seal between the toilet and the flange. A wax ring is the standard seal for a reason — it compresses to fit uneven surfaces and creates a reliable barrier against leaks. Use a wax ring every time.
What if the bolts are stuck and I cannot remove them?
Apply penetrating oil (like WD-40) to the bolts and let it sit for 15 to 30 minutes. Try again with your wrench. If they are still stuck, you can carefully cut them with a hacksaw or angle grinder, but be careful not to damage the flange. Once you have removed the toilet, you can replace the bolts with new ones.
How long does it take to replace a toilet?
Most people complete the job in one to three hours, depending on how easily the old bolts come out and how quickly the new wax ring seals. If you have never done this before, plan for the longer end of that range. The actual work is straightforward, but taking your time reduces the risk of mistakes.
Can I replace a toilet myself if I rent?
Check your lease and contact your landlord first. Most leases require the landlord's permission for repairs or replacements. In many places, the landlord is responsible for maintaining the toilet, so they may want to hire a plumber or provide the new toilet. If your lease allows you to make repairs and your landlord agrees, you can do the work yourself.