How do I replace a toilet?

Replacing a toilet is a one-afternoon job for most homeowners who have a helper, an adjustable wrench, a putty knife, a new wax ring and new floor bolts. The new toilet sits on the same drain and the same water supply, so a like-for-like swap in Virginia usually needs no permit; in a special flood hazard area the building official can require one.^[1] What decides whether the job ends dry is the flange under the old toilet and how you set the new one down.

Before you buy the new toilet

Measure the rough-in. With the old toilet still in place, measure from the finished wall behind it (not the baseboard) to the center of the bolts that hold the bowl to the floor. Buy a toilet made for that distance, or it will sit too far from the wall or will not fit at all.

Choose an efficient model. Federal rules have capped a new gravity-tank toilet at 1.6 gallons per flush since January 1, 1994.^[2] Toilets with EPA's WaterSense label use 1.28 gallons per flush or less, 20 percent less than that standard, and are independently certified for performance as well as efficiency.^[3] EPA notes that the "low-flow" toilets of the 1990s were sometimes associated with performance issues such as double flushing, and that labeled toilets sold today far outperform toilets from the 1980s and 1990s.^[3]

Check for a rebate first. Since October 2024, City of Charlottesville residents can get a rebate of up to $150 per toilet, for up to three toilets, when they replace a toilet that uses 1.6 gallons per flush or more with a WaterSense labeled model, and the rebate can cover the toilet, the installation or both.^[4] The rebate needs the receipt and a form, and the city says the program depends on funding and may be discontinued at any time.^[4] Ask your own water utility whether it runs something similar before you buy.

Gather the parts. You need a wax ring (or a wax-free seal), new closet bolts, a braided supply line, a putty knife, a sponge and bucket, rubber gloves, and cardboard or an old towel to set the old toilet on. Oatey recommends replacing the closet bolts whenever you replace the wax ring,^[5] and suggests considering a new supply line at the same time.^[7]

Getting the old toilet out

Close the valve behind the toilet, then flush while holding the handle down so the tank and bowl empty. Some water stays in the bowl and trap, and water left there can splash out when the toilet comes off the flange,^[6] so sponge it out, use a wet-dry vacuum, or use a water-absorbing gel made for the purpose.

Unscrew the supply line, pop off the decorative bolt caps and take the nuts off. Rock the bowl gently to break the old seal, then lift it straight up.^[5] A toilet is heavy and porcelain chips, so get a helper. Stuff an old rag into the drain opening to block sewer gas while you work, and take it out before the new toilet goes on.

Check the flange before anything goes back

The flange is the fitting in the floor that the toilet bolts to and that joins it to the drain. Scrape every bit of old wax off it with a putty knife, then look at it closely.

• Height. The flange should sit flush with or slightly above the finished floor.^[5] One that sits lower, which often happens after thicker tile goes down over old vinyl, needs a flange spacer or an extra-thick wax ring.^[5]
• No stacking. Never stack two wax rings to make up height; use an extra-thick ring or a flange extender instead.^[5]
• Cracks and rust. A broken flange is the usual reason a toilet rocks even when the bolts are tight. A broken flange ring can often be fixed with a repair ring screwed down over it, but when the drain section of the flange is damaged, a licensed plumber is needed to replace the flange.^[7]
• Soft floor. If a leak brought you here, press on the floor around the opening. Oatey warns that water-damaged subfloor can weaken the fasteners that hold the flange in place.^[5]

Setting the new toilet

Set the new bolts in the flange slots, centered with the flange opening and parallel with the wall behind the tank.^[7] Center the new wax ring on the flange, or on the toilet's outlet if its instructions say so. Lower the bowl straight down over the bolts and press it into the wax with a slight side-to-side twist. Do not rock it: Oatey explains that wax has no memory, so rocking compresses it unevenly and leaves several leak paths.^[9]

Tighten the nuts a little at a time, alternating sides, until the bowl sits firm on the floor. Stop there, because overtightening can crack the porcelain.^[10] If the bowl still rocks on an uneven floor, use plastic toilet shims rather than more force.

A wax ring is single use. Once a wax ring has been compressed it cannot be reused, even if you lift the toilet minutes after setting it.^[8] If you have to pull the toilet back up for any reason, put a new ring on. Wax-free seals are reusable and mess-free, but they may not seal as well on an uneven or damaged flange.^[11]

On a two-piece toilet, fit the tank to the bowl with the gasket and bolts supplied, tightening them by hand and evenly. Connect the supply line hand-tight plus a quarter turn with a wrench, open the valve and let the tank fill.^[5] Flush several times and run a dry paper towel around the base, the tank bolts and both ends of the supply line. Oatey's advice is to caulk the base only after the toilet has passed several flushes with no leaks.^[5]

Stop and call a pro if

• The flange's drain section is cracked, rotted or broken, or it is a brass flange on cast iron. Oatey notes that an old lead bend under a brass flange may have deteriorated beyond repair and need replacing.^[8]
• The floor around the toilet is soft or the ceiling below is stained. The subfloor may need repair before any toilet goes back down.
• The shutoff valve will not close fully, or it leaks when you turn it. Replacing it means working on the supply pipe.
• You want to move the toilet or change the drain. Virginia's building code exempts from a permit the replacement of plumbing fixtures without alteration of the water supply and distribution systems, sanitary drainage systems, or vent systems.^[1] A new drain location is an alteration and a job for a licensed plumber. See whether you can replace your own plumbing fixtures in Virginia.
• The new toilet still leaks at the base after a fresh ring on a sound, level flange. Read why water leaks around the base of a toilet.

Getting help on Loclis

If you would rather not lift porcelain, licensed plumbers on Loclis install toilets. Browse toilet repair and installation, find plumbers in Blacksburg, read what a toilet replacement costs in Virginia, or see every plumbing answer.

When you are ready, describe the toilet job once and licensed local plumbers quote it.