Key Takeaways
- Shut off the water supply at the valve behind the toilet, flush to empty the bowl, and disconnect the water line before you remove the old toilet.
- The toilet is held down by two bolts on either side of the base; you will need a wrench or socket set to loosen them, and the toilet itself weighs 80 to 100 pounds.
- A new toilet comes with a wax ring (the seal between the toilet and the drain pipe) and bolts; you install the wax ring on the drain opening before setting the new toilet in place.
- After the new toilet is bolted down, reconnect the water line, turn the water back on, and let the tank fill and flush once before you use it normally.
- If the bolts are rusted or the wax ring is damaged, the job takes longer, but neither problem requires a plumber.
What You Will Need
Gather these tools and materials before you start. You need an adjustable wrench or a socket set to loosen the bolts, a sponge or wet/dry vacuum to remove water from the bowl and tank, a putty knife to scrape away the old wax ring, and a bucket for any spills. A new wax ring comes with most new toilets, but check the box before you buy — if it is not included, they cost $5 to $15 at any hardware store.
You will also need the new toilet itself. Standard toilets fit the same drain opening (called a 4-inch rough-in, which is the distance from the wall to the center of the drain), but measure yours before you buy to be sure. Bring a tape measure and measure from the wall behind the toilet to the center of the bolts on the floor. If you are replacing an old toilet with a new one of the same type, you can skip this step.
Have a helper on hand if possible. The toilet is awkward to lift and move, and a second person makes the job safer and faster. If you are working alone, take your time and do not rush the lifting.
Turn Off the Water and Empty the Tank
The water shutoff valve is behind the toilet, usually on the left side where the water line enters. Turn it clockwise until it stops — you should feel resistance, not a hard stop. If the valve is stuck or will not turn, do not force it; call a plumber instead, because forcing it can break the valve and flood your home.
Once the water is off, flush the toilet. The tank will empty and the bowl will fill with water from the tank, not from the supply line. Use a sponge or wet/dry vacuum to remove as much water as possible from the bowl. Some water will remain in the trap (the curved part inside the bowl), and that is normal — you cannot remove it all, so have a bucket ready when you disconnect the water line.
Disconnect the water line by turning the nut at the base of the fill valve (where the line enters the tank) counterclockwise with an adjustable wrench. The line will drip, so position your bucket underneath. If the nut is stuck, apply penetrating oil and wait 15 minutes before trying again.
Remove the Old Toilet
The toilet is held down by two bolts, one on each side of the base. These bolts go through the toilet base and into the floor flange (a ring-shaped fitting in the floor). You will see plastic or metal caps covering the bolt heads; pry these off with a flathead screwdriver. If they are stuck, spray them with penetrating oil and wait a few minutes.
Use an adjustable wrench or socket set to loosen both bolts. Turn counterclockwise until they are loose enough to remove by hand. If a bolt is rusted and will not turn, spray it with penetrating oil, wait 15 to 30 minutes, and try again. Do not strip the bolt by forcing it — patience works better than force.
Once both bolts are removed, the toilet is free to lift. Straddle the toilet, grip it on both sides of the tank, and lift straight up. The toilet is heavy (80 to 100 pounds) and awkward, so move slowly and keep your back straight. Set it on its side on a tarp or old towels to protect your floor. Water will spill from the trap, so have towels ready.
After the toilet is out, you will see the wax ring still stuck to the floor flange. Scrape it away with a putty knife, working carefully to avoid damaging the flange itself. Once the old wax is gone, inspect the flange for cracks or damage. If it is cracked, it needs to be replaced before you install the new toilet — this is a job for a plumber.
Install the Wax Ring and Set the New Toilet
The wax ring is a soft, sticky ring that seals the gap between the toilet base and the drain opening. It comes compressed in a cardboard tube and softens when you handle it. Remove it from the package and press it firmly onto the bottom of the new toilet, centered over the drain hole. The wax should stick to the toilet base without falling off.
Position the new toilet over the floor flange, aligning the bolt holes in the toilet base with the bolts sticking up from the flange. Lower the toilet slowly and evenly, pressing down as you go. The wax ring will compress and create a seal. Do not rock the toilet side to side once it is down — rocking breaks the seal. Press down firmly on the tank and bowl to seat the toilet fully.
Once the toilet is in place, thread the bolts through the holes in the base and tighten them by hand first. Then use a wrench to tighten them evenly — tighten one bolt a quarter turn, then the other, then back to the first. This keeps the toilet level. Tighten until the bolts are snug, but do not over-tighten; you can crack the porcelain. The bolts should be tight enough that the toilet does not rock, but loose enough that you can still turn them with a wrench.
Reconnect the Water Line and Test
Reconnect the water line by threading the nut back onto the fill valve and tightening it by hand first, then with a wrench. Tighten until it is snug — again, do not over-tighten. Turn the shutoff valve counterclockwise to turn the water back on. The tank will fill slowly at first; this is normal.
Once the tank is full, flush the toilet and watch for leaks. Check under the tank and around the base where the wax ring seals. If water is dripping from the water line connection, tighten the nut a quarter turn. If water is seeping from under the base, the wax ring did not seal properly — you will need to remove the toilet and install a new wax ring.
Let the tank fill and flush a second time to make sure everything is working. Check again for leaks. If there are no leaks and the toilet flushes normally, you are done.
Common Problems and How to Fix Them
Rusted bolts: If the bolts will not loosen, spray them with penetrating oil (like WD-40 or Liquid Wrench), wait 15 to 30 minutes, and try again. If they still will not move, apply more oil and wait longer — sometimes overnight. As a last resort, use a hacksaw to cut the bolt in half, then remove the pieces. New bolts come with the new toilet, so you will have replacements.
Wax ring did not seal: If water seeps from under the base after the first flush, turn off the water, remove the toilet, and install a new wax ring. This usually means the wax was not pressed firmly enough onto the toilet base, or the toilet was rocked after it was set down. The second time, press the wax on harder and lower the toilet more slowly.
Water line leaks: If the connection between the water line and the fill valve drips, turn off the water and tighten the nut a quarter turn. If it still leaks, turn off the water, disconnect the line, and inspect the nut and the valve for damage. If the nut is cracked or the valve is damaged, the fill valve or water line will need to be replaced — this is a separate job from the toilet replacement.
When to Call a Plumber
You can handle most toilet replacements yourself, but a few situations call for professional help. If the shutoff valve will not turn or is leaking, if the floor flange is cracked or damaged, if the bolts are so rusted they cannot be removed, or if water continues to leak from under the base after you have installed a new wax ring, a plumber can fix these problems faster than troubleshooting them yourself.
If you are not comfortable lifting the old toilet or working with the bolts, a plumber can remove the old toilet and install the new one for you. This usually costs $150 to $300 in labor, depending on your area and how difficult the removal is.
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 a wrench, a screwdriver, and a putty knife. If the bolts are rusted or the shutoff valve is stuck, a plumber can help, but the basic job is within reach for most people.
How long does it take to replace a toilet?
If everything goes smoothly, the job takes two to three hours from start to finish. If bolts are rusted or the old wax ring is stubborn to scrape away, it can take four to five hours. Most of that time is waiting for penetrating oil to work on stuck bolts, not active work.
Can I reuse the old bolts?
New toilets come with new bolts, and you should use them. Old bolts are often corroded or damaged, and new ones are inexpensive and may provide to fit. If you run out of new bolts, hardware stores sell toilet bolt kits for $5 to $10.
What if the new toilet does not fit?
Measure the rough-in (distance from the wall to the center of the drain bolts) before you buy. Standard toilets are 12 inches, but some are 10 or 14 inches. If you buy the wrong size, most stores will accept a return or exchange. Measure twice before you buy.
Is the wax ring reusable?
No. Once a wax ring is compressed and removed, it loses its seal. Always install a new wax ring when you replace a toilet. They cost $5 to $15 and are essential to preventing leaks.