How to Replace a Toilet: Remove, Reset the Wax Ring and Seal

How to replace a toilet: shut off the water, flush and sponge out the bowl and tank, disconnect the supply line, unbolt the old toilet, lift it out, clean and check the flange, set a new wax ring and the new bowl, bolt it down evenly, mount the tank, reconnect the water and test for leaks.

Toilets are heavy, so get a helper.

How to replace a toilet: before you start

Check the rough-in, the distance from the wall to the center of the drain, which is commonly 12 inches. The new toilet must match it. Measure, and buy a toilet with the same rough-in and a bowl shape that fits the space. Buy a new wax ring, closet bolts and a supply line.

Quick facts: how to replace a toilet
Time	About 2 to 3 hours
Tools	Adjustable wrench, putty knife, bucket, sponge, level, screwdriver, hacksaw for bolts
Parts	New toilet, wax ring (or wax-free seal), closet bolts, supply line, caulk if desired
Help	Two people for lifting

Step by step

1. Shut off the water at the stop valve behind the toilet.
2. Flush to empty the tank, then sponge out the rest of the water from the tank and bowl.
3. Disconnect the supply line from the bottom of the tank.
4. Remove the tank if you want a lighter lift, by undoing the bolts under it.
5. Pry off the caps over the base bolts and remove the nuts.
6. Rock the bowl gently to break the wax seal, then lift it straight up and set it on an old towel or newspaper. Expect some water to spill.
7. Scrape off the old wax from the flange and stuff a rag in the drain to block sewer gas while you work.
8. Inspect the flange. It should be solid, level with or just above the finished floor and free of cracks or rot.
9. Set the new wax ring on the flange, or on the bottom of the bowl as the instructions say, with the closet bolts upright in the flange slots.
10. Lower the bowl straight down over the bolts and press down firmly, without twisting.
11. Fit washers and nuts and tighten alternately a little at a time. Stop when the toilet is snug and level. Over-tightening can crack porcelain.
12. Mount the tank with its rubber gasket and bolts, then connect the supply line, turn on the water and let it fill.
13. Flush several times and look for leaks at the base, the tank and the supply connection.

Flange problems

Problem	What to do
Flange below the floor surface	Use a flange extender or spacer
Cracked or rusted flange	Repair ring or replacement; may need a plumber
Rotted subfloor	Repair the floor before setting the toilet
Rocking toilet	Shim and caulk the base after leveling

Choosing the right toilet

Look at rough-in, bowl height and shape, flush performance and water use per flush. A comfortable-height elongated bowl suits many people, and a round bowl saves a little space. Single-flush and dual-flush models both work well.

After the job

Wait 24 hours before caulking around the base, if you want a bead there, so any slow leak shows. Keep an eye out for damp patches around the flange for the first few days, and check the ceiling below if the bathroom is upstairs.

When to call a professional

If the flange is broken, the subfloor feels spongy, the toilet will not seal or the drain line is partly blocked, a plumber can repair it before you set the new bowl. Knowing how to replace a toilet makes it easier to tell whether you have a simple swap or a bigger repair.

How to replace a toilet: the parts to buy

Before you buy a new toilet, confirm the rough-in distance from the wall to the bolt centre, since a mismatch means the new bowl will not sit flush. Replacing a toilet also means choosing a new wax ring or seal, a supply line, and new closet bolts, which are cheap and often corroded. Learning how to replace a toilet cleanly means setting the bowl level before you tighten the bolts, then testing for leaks with a flush and a close look at the base. Keep the old closet bolts only if they are undamaged.

The job is easier when you know how to replace a toilet in the right order: remove the old unit, then set the new flange.

Related reading

• Toilet Leaking at Base: Causes and What to Do Next
• How to Fix a Running Toilet: Flapper, Float and Fill Valve
• How to Replace a Toilet Fill Valve: Steps for a Quiet Refill
• Toilet Not Filling With Water? Causes and Simple Fixes

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