How to Replace a Toilet
Updated February 20, 2026
Remove an old toilet and install a new one -- drain, pull, set the wax ring, position the bowl, attach the tank, and test for leaks without cracking the porcelain.
Overview
Replacing a toilet is a 1-2 hour project most homeowners can handle. Common reasons: cracked bowl or tank, persistent base leak that a new wax ring did not fix, upgrading from an old 3.5-5 gallon per flush model to a modern 1.28 GPF, or just updating the look. The process: disconnect the old toilet, inspect the flange, set a new wax ring, position and bolt the new bowl, attach the tank, connect the supply. The hardest part is the weight -- a porcelain bowl runs 50-60 pounds, tank adds 20-30 more. A helper makes a big difference.
What You'll Need
Safety First
- Toilets are heavy and awkward -- 50-60 pounds with no comfortable handles. Lift with your legs. Get a helper for removal and positioning.
- Once the toilet is off, the open flange exposes your home to sewer gas. Stuff a rag in the opening immediately. Remove it before setting the new toilet -- do not forget it is down there.
- Do not overtighten the closet bolts. Porcelain cracks easily under uneven pressure. Alternate sides (left, right, left, right) and stop when the toilet is solid and does not rock. Crack it and the whole toilet is ruined.
Step-by-Step Instructions
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Drain and Disconnect the Old Toilet
Water supply valve off (clockwise). Flush and hold the lever to drain the tank. Sponge out whatever water remains in the tank and bowl -- there is always some. Disconnect the supply line from the tank bottom with an adjustable wrench, bucket underneath. Pop the decorative caps off the closet bolts and remove the nuts. Rusted nuts that will not turn? Cut the bolts with a hacksaw.
Tip: Stuff towels around the base before you lift. Even after sponging, water will spill when the toilet comes up. Towels protect the floor and make cleanup easy. -
Remove the Old Toilet
Rock the toilet gently side to side to break the wax seal. Lift straight up off the bolts -- 50-60 pounds, helper recommended. Set it on cardboard or an old sheet. Immediately stuff a rag into the open flange to block sewer gas. Scrape all old wax from the flange and floor with a putty knife. Remove the old closet bolts. Inspect the flange: should be level with or slightly above the finished floor, not cracked, bolt slots intact. Damaged flange needs repair before the new toilet goes on.
Tip: Flange below the floor (common after new flooring is laid over the original)? Use a flange extender or extra-thick wax ring. A low flange is the most common reason toilet installations leak at the base. -
Set New Closet Bolts and the Wax Ring
New closet bolts into the flange slots, evenly spaced (equal distance from wall on each side), pointing straight up. Some kits include a washer to hold the bolt upright -- use it. Place the wax ring on the flange, centered over the opening, tapered side (if it has a plastic funnel) pointing down into the drain. You can also press the ring onto the toilet outlet instead -- either works, but flange placement is easier for alignment.
Tip: Wax-free seals (Fluidmaster Better Than Wax, Danco Perfect Seal) are an excellent upgrade. Reusable if you need to reposition, work at any flange height, and more forgiving than wax. Cost $5-10 more and worth every penny. -
Position and Secure the New Toilet Bowl
Remove the rag from the flange. Lift the bowl and lower it onto the closet bolts, aligning the holes in the base. Press down firmly and evenly to compress the wax ring. Gentle rocking to settle, then full body weight to fully compress. Do not lift the toilet once it touches the wax -- lifting breaks the seal. Check level (front to back, side to side). Rocks? Plastic shims under the base. Install washers and nuts, tighten alternately (few turns left, few turns right) until snug. Do not overtighten.
Warning: Once the toilet touches the wax ring, it does not come back up. If you need to reposition, you need a new wax ring. This is the best argument for wax-free seals -- they allow repositioning without replacement. -
Attach the Tank (Two-Piece Toilets)
Two-piece toilet? Tank goes on next. Place the tank-to-bowl gasket (large rubber washer) onto the flush valve opening on the bottom of the tank (some are pre-installed). Set the tank on the bowl, align bolt holes. Insert tank bolts from inside the tank with rubber washers on both sides. Hand-tighten nuts from below, then alternate half turns on each bolt until the tank is level and snug. Do not overtighten -- porcelain cracks.
Tip: Check tank level after every half turn on each bolt. One side tighter than the other and the tank sits crooked -- or cracks. Alternate and keep pressure even. -
Connect Water Supply and Test
Connect the supply line to the fill valve at the bottom of the tank. Hand-tight plus a quarter turn. Turn on the supply valve slowly. While the tank fills, check the supply line connection, tank bolts, and base for leaks. Let the tank fill, then flush 3-4 times. After each flush, check the base for water -- if there is any, the wax ring did not seal. Check behind the toilet for drips from tank bolts or supply line. Everything dry? Caulk the base where it meets the floor, leaving a gap at the back (leak detection -- see tip). Trim the closet bolts with a hacksaw if they stick up above the caps, snap caps in place.
Tip: Leave a 4-inch gap in the caulk at the back of the toilet. If the wax ring ever fails, water appears there first and alerts you to the problem. Fully caulked? Water pools unseen under the toilet and damages the subfloor for months before you notice.
Pro Tips
- Measure the rough-in before you shop. That is the distance from the wall to the center of the closet bolts. Standard is 12 inches, but 10 and 14 exist. Wrong rough-in means it will not fit or leaves an awkward gap.
- Comfort height toilets (ADA height, right height) are 17-19 inches from floor to seat vs the standard 15. Much easier to sit and stand, especially for taller people or anyone with knee issues. Minimal price difference.
- Cracked flange or broken bolt slots? A flange repair ring ($5-10) bolts on top and gives you new slots. Much easier than replacing the whole flange, which means cutting the drain pipe.
- Two-piece toilets are easier to install because you carry each piece separately. One-piece looks sleeker but weighs 80-100 pounds and goes in as one heavy, awkward unit.
- Applied silicone caulk around the base? Do not use the toilet for 24 hours while it cures. No caulk or just a thin bead? Ready for immediate use.
When to Call a Pro
Call a plumber if the flange is severely damaged and needs full replacement (cutting the drain pipe), if the flange is too low for an extender to fix, if the drain pipe is corroded cast iron, or if you need to move the toilet to a different position (major drain relocation). Straightforward swap on an intact flange? Absolutely doable as DIY.