What You Need to Do Before You Start
Replacing a toilet is a job most homeowners can do in two to three hours with basic tools and no plumbing experience. The work breaks into three parts: shutting off the water and draining the old toilet, removing it, and installing the new one. You will need an adjustable wrench, a screwdriver, a putty knife, a bucket, and a wax ring (the seal between the toilet and the floor). The hardest part is usually breaking the old caulk loose, not the plumbing itself.
Before you buy a new toilet, measure the rough-in distance — the distance from the wall behind the toilet to the center of the bolts that hold it down. Standard rough-in is 12 inches, but some older homes have 10-inch or 14-inch rough-ins. If you buy the wrong size, it will not fit. Check your current toilet's measurements or look at the specifications on the box of any toilet you are considering.
Key Takeaways
- Measure your rough-in distance before buying a new toilet, because a 12-inch rough-in is standard but some homes need 10 or 14 inches.
- Turn off the water at the shutoff valve under the tank, flush to empty the bowl, and use a bucket to catch water that remains in the trap.
- Remove the old toilet by unbolting it from the floor, then scrape away the old wax ring completely before setting the new one in place.
- Set the new toilet on the wax ring, bolt it down hand-tight, reconnect the water supply, and let the tank fill before flushing.
- Caulk around the base of the toilet after installation, leaving a small gap at the back so water can escape if a leak occurs inside the bowl.
Turn Off the Water and Empty the Tank
Locate the shutoff valve on the water line under the toilet tank. Turn it clockwise until it stops — you should feel resistance, not a hard stop. If the valve is stuck or will not turn, you may need to shut off the main water supply to the house instead. Flush the toilet once to empty the tank and bowl as much as possible.
Water will still be trapped in the bowl below the waterline. Use a bucket and a cup or small hand pump to remove this water. You can also use a wet/dry shop vacuum if you have one. This step prevents water from spilling across your floor when you disconnect the supply line and remove the toilet. Disconnect the water supply line by turning the nut at the base of the fill valve counterclockwise with your adjustable wrench.
Remove the Old Toilet
The toilet is bolted to the floor through two bolts on either side of the base. These bolts are usually covered by plastic caps that pry off with a screwdriver. Once the caps are off, use your wrench to remove the nuts holding the bolts. If the nuts spin but will not come loose, hold the bolt head steady with a second wrench while you turn the nut. If a bolt is rusted and will not budge, spray it with penetrating oil and wait 15 minutes, then try again.
Once both bolts are loose, rock the toilet gently side to side to break the seal between the wax ring and the floor. Lift the toilet straight up and set it on its side in your bathtub or on a tarp outdoors — it will be heavy and may still contain water. Do not drop it or set it down hard, as the porcelain can crack.
Scrape away all the old wax ring material from the floor using a putty knife. Get down to bare floor or flange. If any wax remains, the new toilet will not sit level. Once the floor is clean, stuff a rag into the drain opening to block sewer gases and prevent anything from falling in.
Install the New Wax Ring and Toilet
Remove the rag from the drain opening. Press a new wax ring onto the underside of the new toilet's outlet — the hole on the bottom of the bowl. The wax should stick to the porcelain without additional fasteners. Some wax rings come with a plastic or rubber flange that goes on first; follow the instructions on your specific ring.
Carefully lower the new toilet onto the bolts, aligning the outlet with the drain opening. Press down firmly and evenly until the toilet sits flat on the floor. The wax ring will compress and create a watertight seal. Hand-tighten the bolts on both sides, then use your wrench to snug them down — turn each bolt a quarter turn at a time, alternating sides, until the toilet no longer rocks. Do not over-tighten; you can crack the porcelain or the flange underneath.
Reconnect the Water Supply and Test
Reconnect the water supply line by turning the nut clockwise by hand first, then tightening it with your wrench. Turn the shutoff valve counterclockwise to restore water pressure. The tank will fill automatically. Listen for the fill valve to shut off once the tank reaches full level — this usually takes one to two minutes.
Flush the toilet and watch for leaks around the base and at the water connection. If water pools around the base, the wax ring may not have seated properly. If the connection leaks, tighten the supply line nut slightly. If the base leaks and tightening does not help, you will need to remove the toilet and reset the wax ring. Most leaks appear within the first flush or two.
Caulk the Base and Finish
Once you confirm there are no leaks, caulk around the base of the toilet using silicone caulk and a caulk gun. Run a bead around the entire perimeter where the toilet meets the floor. Smooth it with a wet finger or caulk tool. Leave a small gap (about one inch) at the back of the toilet where it meets the wall — this allows water to escape if a leak occurs inside the bowl, rather than pooling under the toilet.
Let the caulk cure for 24 hours before using the toilet heavily. Replace the plastic caps over the bolts if your toilet came with them. Your new toilet is now installed and ready to use.
Common Problems and How to Fix Them
If the toilet rocks side to side after installation, the bolts are not tight enough or the floor is not level. Tighten the bolts a quarter turn at a time on each side. If the floor slopes, you may need shims — thin plastic wedges that slide under the base to level the toilet. Most hardware stores carry toilet shims.
If water leaks from under the toilet when ready after installation, the wax ring did not seal properly. This usually means the toilet is not sitting flat or the old wax was not completely removed. You will need to remove the toilet, scrape the floor clean again, and reset it with a new wax ring. If water leaks from the connection at the supply line, tighten the nut with your wrench — usually a quarter turn is enough.
If the fill valve runs continuously or the toilet hisses, the problem is inside the tank, not the installation. Most fill valves can be adjusted or replaced without removing the toilet. Consult the manual that came with your toilet or the manufacturer's website for your specific model.
Frequently Asked Questions
Do I need a plumber to replace a toilet?
No. Toilet replacement is one of the most straightforward plumbing jobs a homeowner can do. The only tools you need are an adjustable wrench, a screwdriver, and a putty knife. If you are uncomfortable working with water lines or your shutoff valve is stuck, a plumber can handle it, but the job itself does not require a license.
What if my old toilet is glued to the floor?
Some toilets are caulked so heavily that they are difficult to remove. Use a utility knife to cut through the caulk all the way around the base before you try to lift the toilet. If the toilet still will not budge, spray penetrating oil around the base and wait 30 minutes. Rock it gently side to side — do not yank straight up, as you can crack the porcelain.
Can I reuse the old wax ring?
No. Wax rings are single-use and lose their seal once they are compressed. A used wax ring will not create a watertight seal on the new toilet. Always buy a new wax ring when you replace a toilet. They cost between $3 and $8.
How long does a new toilet last?
A standard toilet bowl lasts 20 to 30 years if it is not cracked or damaged. The internal fill valve and flapper usually need replacement after 10 to 15 years of use. If your toilet is leaking from inside the tank or running constantly, the internal parts may be worn out, but the bowl itself is probably fine and can be repaired.
What is the difference between a wax ring and a wax-free ring?
Wax rings are the traditional choice and work well in most homes. Wax-free rings use rubber or foam and are easier to handle because they do not stick to your hands. Both seal equally well. Wax-free rings cost slightly more but are worth it if you find wax messy. Choose whichever you are more comfortable using.