Replacing a toilet is one of the most approachable DIY plumbing projects — no soldering, no wall demolition, just careful lifting and a good wax seal. This guide covers full replacement, plus how to “reset” your existing toilet (pull it, replace the wax ring, and set it back) when the toilet itself is fine but leaking at the base.
Part 1: Resetting your existing toilet (wax ring replacement)
Water pooling around the base of the toilet usually means one thing: the wax ring sealing the toilet to the floor drain has failed. You don’t need a new toilet — you need a new $10–$20 wax ring and about an hour. (A plumber typically charges $150–$300 nationally for this same job.) Our guide to a toilet leaking at the base covers each cause in turn, how to tell a true base leak from water that starts higher up, and where the line sits between a repair you can try and work for a plumber.
Tools and materials
- New wax ring (with or without the plastic horn — either works)
- Adjustable wrench or channel-lock pliers, putty knife, bucket and sponge
- Rubber gloves, old newspapers or a tarp
- Replacement closet bolts if the old ones are corroded
Steps
- Shut off the water at the fixture valve behind the toilet (turn clockwise). No fixture valve? Shut off the house main.
- Drain the toilet. Flush, holding the handle down to empty the tank. Scoop remaining water from tank and bowl with a cup, then sponge out the rest into a bucket.
- Disconnect the supply line from the fill valve tailpiece (unscrew by hand or with channel-lock pliers) and pop the caps off the floor bolts.
- Remove the nuts and washers from the closet bolts with a wrench.
- Lift the toilet straight up — lift with your legs, not your back — and set it on newspaper or a tarp. Stuff a rag in the open drain to block sewer gas.
- Scrape off the old wax from the toilet’s underside (especially the “horn,” the round outlet) and from the floor flange, using a putty knife. The surfaces must be clean for a good seal.
- Set the new wax ring. Warm it slightly (a sunny spot or near a heat vent) so it’s pliable, peel the wrapper, and press it onto the flange — cone/horn side down into the drain. Replace the closet bolts now if needed, spacing them evenly.
- Reset the toilet. Lower it straight down over the bolts, keeping it square to the wall. Press down firmly and rock gently side to side to compress the wax evenly. Do not lift it back up — breaking the fresh seal means starting over with a new ring.
- Tighten, reconnect, test. Snug the closet-bolt nuts alternately, a little at a time — overtightening cracks porcelain. Trim excess bolt length with a hacksaw and snap on the caps. Reconnect the supply line, turn the water on, flush several times, and check the base and supply connection for leaks.
Part 2: Installing a brand-new toilet
If the toilet is cracked, chronically clogged, or an ancient water-guzzler, replacement makes more sense than resetting. Steps 1–9 below assume the old toilet is already out (follow the removal steps in Part 1).
Before you buy: measure the rough-in
Measure from the finished wall behind the toilet to the center of the closet bolts. Twelve inches is standard; 10- and 14-inch models exist for non-standard rough-ins. Bring the measurement to the store.
Removal recap
- Turn off the supply valve (clockwise to close; quarter-turn valves need only a quarter turn).
- Flush repeatedly and sponge out remaining water; set the tank lid somewhere safe.
- Disconnect and discard the old supply line — braided supply lines should be replaced every 3–5 years anyway.
- Remove the closet-bolt nuts (cut away any caulk at the base with a utility knife first).
- Lift the toilet off (a helper makes this much easier; you can separate the tank from the bowl to lighten the load), plug the drain with a rag, and scrape the old wax off the flange.
Installation
- Set new closet bolts in the flange slots, heads down, slid to the narrow ends.
- Place the new wax ring on the flange, narrow/horn end down.
- Set the bowl straight down over the bolts, press and rock gently to seat the wax. Don’t lift it again once set.
- Tighten the bolts alternately, just snug — porcelain cracks easily. Trim excess bolt and press on the decorative caps.
- Mount the tank: place the tank-to-bowl gasket on the tank bottom, drop the tank bolts through, set the tank on the bowl, and tighten evenly.
- Connect a new braided supply line from the shutoff valve to the fill valve tailpiece.
- Turn the water on (counterclockwise to open), let the tank fill, and flush. Check the base, tank bolts, and supply connections for leaks.
- Caulk the base — front and sides only. Leave the back uncaulked so a future leak reveals itself instead of rotting the subfloor silently. Use 100% silicone caulk and let it cure about a day before mopping.
When to get help
Call in a professional if the flange is cracked or sits below floor level, the subfloor is soft or rotted, or the toilet rocks after installation despite your best shimming — those point to structural or flange problems beyond a standard install.
America’s Service Plumber is a free matching service. We’ll connect you with licensed local plumbers in your area for free quotes on toilet installation and repair — no obligation. Get a free quote.
