What You Need to Do Before You Start
Replacing a toilet is a job you can do yourself if you have basic tools and are willing to follow the steps in order. The work takes two to four hours and does not require a plumber, though you will need to turn off the water supply, drain the bowl, and unbolt the old toilet from the floor. Most of the difficulty is in the physical removal — the new one goes in much faster than the old one comes out.
Before you buy a new toilet, measure the rough-in distance. This is the distance from the wall behind the toilet to the center of the bolts that hold it to the floor. Standard rough-in is 12 inches, but some bathrooms have 10-inch or 14-inch rough-ins. If you install a toilet with the wrong rough-in, it will not sit flush against the wall or will hit the wall entirely. Check your current toilet by measuring from the wall to the center of the bolts, or look at your home's original blueprints if you have them.
Key Takeaways
- Measure your rough-in distance (wall to bolt center) before buying a new toilet, because installing the wrong size leaves a gap or makes the toilet hit the wall.
- Turn off the water at the shutoff valve under the tank, flush to empty the bowl, and use a wet/dry vacuum or sponge to remove remaining water before unbolting.
- The old wax ring sticks to the floor and must be scraped away completely; leaving pieces behind causes leaks under the new toilet.
- Set the new toilet in place without the bolts first, check that it sits level and does not rock, then bolt it down and reconnect the water supply.
- Do not overtighten the bolts — hand-tight plus a quarter turn is enough; over-tightening cracks the porcelain.
Gather Your Tools and Materials
You will need an adjustable wrench or socket set, a screwdriver (usually Phillips), a putty knife or old chisel, a wet/dry vacuum or large sponge, a bucket, and a new wax ring. The wax ring is the seal between the toilet and the drain pipe — it comes with most new toilets, but if yours does not, buy one separately. You also need a new fill valve and flapper kit if your old toilet's tank parts are worn, though many people reuse the old tank hardware if it still works.
Wear old clothes and have towels ready. Even though you will drain the bowl, water always spills during removal. A helper makes the job easier because a toilet is heavy and awkward to lift, but one person can do it by tilting it slightly and sliding it out.
Turn Off Water and Drain the Bowl
Locate the shutoff valve under the tank on the left side. Turn it clockwise until it stops. If the valve is stuck or broken, turn off the main water supply to the house instead. Flush the toilet once to empty the tank and bowl as much as possible.
Use a wet/dry vacuum to suck out the remaining water in the bowl, or use a large sponge to soak it up and wring it into a bucket. Do not skip this step — water will spill when you remove the toilet, and the less water in the bowl, the less mess you make. Disconnect the water supply line by turning the nut at the base of the fill valve with an adjustable wrench. Have a bucket ready because a little water will drip out.
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 snap off or screw off. Remove the caps, then use an adjustable wrench to loosen and remove the nuts. If the bolts spin and will not come off, hold the bolt head with a second wrench while you turn the nut.
Rock the toilet gently side to side to break the seal of the wax ring, then lift it straight up and set it on its side on a towel or in a bathtub. The toilet is heavy — typically 80 to 100 pounds — so get help if you can. Once it is out of the way, you will see the old wax ring stuck to the floor around the drain opening.
Scrape away every bit of the old wax ring with a putty knife or old chisel. Wax is sticky and takes time, but it must be completely removed. Any wax left behind will prevent the new ring from sealing, and water will leak under the toilet and rot the subfloor. Once the floor is clean and smooth, place a rag over the drain opening to block sewer gases and prevent anything from falling in.
Install the New Toilet
Remove the rag from the drain and press the new wax ring onto the bottom of the new toilet, centered over the outlet. Some wax rings are sticky enough to stay in place; others need you to hold them. Set the new toilet over the drain opening and lower it slowly onto the bolts. Do not press down hard yet — just let the toilet rest on the wax ring.
Check that the toilet sits level using a spirit level placed on the rim. If it rocks or tilts, lift it slightly and shim under the base with plastic shims or thin metal shims until it is level. A rocking toilet will crack over time and will never seal properly. Once it is level, press down firmly to compress the wax ring, then thread the bolts through the base and hand-tighten the nuts.
Tighten the nuts evenly — a quarter turn on one side, then a quarter turn on the other — until the toilet no longer moves. Stop there. Over-tightening cracks the porcelain base. The bolts should be snug but not cranked down with all your strength. Trim the bolts flush with the nuts using a hacksaw if they stick up too far, then snap the plastic caps back on.
Reconnect the Water Supply and Test
Reconnect the water supply line by threading the nut back onto the fill valve and tightening it with an adjustable wrench. Turn the shutoff valve counterclockwise to restore water to the tank. The tank will fill; listen for the fill valve to shut off when the tank is full. If water keeps running, the fill valve is faulty and needs to be replaced.
Flush the toilet several times and watch for leaks under the base. A small amount of condensation on the outside of the tank is normal, but water pooling under the toilet means the wax ring did not seal. If that happens, you will need to remove the toilet again, scrape away the old wax ring, and install a new one. Check the bolts after the first few flushes — sometimes they loosen slightly as the wax ring settles, and a quick quarter-turn tightens them back up.
Common Mistakes to Avoid
The most common error is leaving pieces of the old wax ring on the floor. Even a small chunk of wax prevents a seal, and water will leak under the toilet within days or weeks. Take your time scraping the floor completely clean. The second mistake is over-tightening the bolts, which cracks the base of the toilet and creates a leak that cannot be fixed without replacing the toilet again.
A third mistake is installing a toilet with the wrong rough-in. A 10-inch toilet in a 12-inch rough-in leaves a gap between the tank and the wall that looks bad and collects dust. A 14-inch toilet in a 12-inch rough-in will not fit at all. Measure before you buy, and if you are unsure, take a photo of your current toilet and show it to the store staff.
Frequently Asked Questions
Do I need to replace the wax ring every time I remove the toilet?
Yes. The wax ring is a one-time seal that compresses when you install the toilet. Once you remove the toilet, the ring is damaged and will not seal again. Always use a new wax ring when you reinstall a toilet, even if you are just moving it a few inches.
What if the bolts are rusted and I cannot remove them?
Spray the bolts with penetrating oil and wait 15 to 30 minutes. If they still will not turn, use a hacksaw to cut through the bolt above the nut, then remove the nut and pull the bolt out. You can replace the bolts with new stainless steel ones when you install the new toilet.
Can I use a new toilet with an old tank?
No. Toilets are sold as complete units — tank and bowl together — and they are not interchangeable. The tank bolts to the bowl in a specific way, and mixing old and new parts causes leaks and poor flushing.
How do I know if the new toilet is installed level?
Use a spirit level placed on the rim of the bowl. The bubble should sit in the center of the level. If the toilet tilts toward the front or back, shim under the base until it is level. A level toilet flushes better and lasts longer.
What should I do with the old toilet?
Most waste management services will pick up a toilet as a bulk item if you call ahead. Some recycling centers accept porcelain. Do not leave it on the curb without calling first — many municipalities require advance notice. You can also contact a local plumber or home improvement store to ask about disposal options.