To install a toilet, you shut off the water, remove the old one and check the flange on the floor. Then you set a new wax ring, lower the bowl onto the bolts, tighten evenly, connect the supply line and test for leaks. Done carefully, it takes a few hours.
Two things decide whether the job is easy. The first is whether the new toilet fits the rough-in, the distance from the wall to the center of the drain. The second is the shape of the flange, the ring that anchors the toilet and seals the drain.
This guide walks through the work at a high level so you can decide whether to do it or hand it off.
Check the fit before you buy
Toilets are built for a specific rough-in, which is the distance from the finished wall to the center of the drain. Measure yours before shopping, then check the new toilet's label or spec sheet for the one it needs. A mismatch leaves the bowl either pinned against the wall or sitting out into the room.
Check the room as well. Look at the space beside the bowl, the position of the door, and the height of any cabinet or tank that sits near the toilet. A bowl that is longer or taller than the old one can be hard to use even if it fits the drain.
Bring the old toilet's model and your measurement when you shop. A dealer can match the new one to your drain in a minute.
Setting the toilet, step by step
Shut off and drain
Close the stop valve behind the toilet, flush, and sponge out what remains in the tank and bowl. Disconnect the supply line.
Lift out the old toilet
Remove the nuts at the base, rock the bowl gently and lift straight up. Stuff a rag in the drain opening to block sewer gas and scrape off the old wax.
Inspect and fix the flange
Look for cracks, rust, a loose ring or a flange sitting below the finished floor. Repair or replace it before the new toilet goes on.
Set the new bowl
Place the wax ring or seal, lower the bowl straight onto the bolts, press down and tighten the nuts a little at a time on alternate sides.
Connect and test
Attach the tank if separate, connect the supply line, open the stop valve slowly and flush several times while checking the base and each joint for water.
Older Sidney homes, hard water and the permit call
The City of Sidney's own plan estimates that roughly 30 percent or more of its housing was built before 1950. In an older house, the flange may be cast iron that has corroded, or it may sit on a floor that has been covered with new tile. Expect to look at the flange closely, and plan for a repair before the bowl goes down.
The city's 2022 water quality report listed total hardness of about 113 ppm, in the moderately hard range on the USGS scale. Minerals can foul the fill valve over time, so if you are buying a new toilet, choose one with a fill valve that is easy to find and replace.
For the permit, the Sidney-Shelby County Health Department says anyone doing plumbing work in Shelby County needs to apply for a permit, with minor repair exempt. Swapping a toilet in the same spot is different from moving one, so call 937-498-7249 and describe your job to find out which applies.
Call and we will check the fit, the flange and the price before work starts.
What the flange tells you
Flange is solid and level with the floor
This is the easy case. A new wax seal and new bolts are all that is needed.
Flange is cracked or rusted
A repair ring or a replacement flange fixes it. Do not set a toilet on a broken ring, because it will rock and the seal will fail.
Flange sits below the finished floor
New flooring has raised the floor. A spacer or extension brings the flange up so the seal can compress. This is a common surprise in remodels.
Floor around the flange is soft
Soft wood means a long-running leak. Stop, find the cause and repair the subfloor before any toilet goes back.
Doing it yourself and calling a plumber
Reasonable to do yourself
- A like-for-like swap on a sound flange and a sound floor.
- Replacing the supply line and stop valve if they turn freely.
- Setting the bowl and tank and checking for leaks.
- Calling the Health Department to ask about a permit.
Call a plumber when
- The flange is cracked, corroded or below the floor.
- The floor around the toilet is soft or stained.
- You are moving the toilet or the drain.
- The stop valve will not close or the pipe is old and brittle.
Mistakes that cause leaks and rocking
The most frequent error is over-tightening. Porcelain cracks, and the crack often does not show until the bowl leaks. Tighten the nuts a little at a time, alternating sides, until the bowl is firm and no more.
A close second is reusing an old wax ring. A ring that has been compressed once does not reseal well. Use a new one every time the toilet comes up, even if you only lifted it to replace a floor.
The third is skipping the shim step when the floor is not flat. A toilet that rocks wears the seal and leaks into the subfloor. Use plastic shims under the base, then trim and caulk around it so water does not travel under the bowl.
Working beyond one toilet
Some toilet jobs belong with larger plumbing work, such as a bathroom remodel where the drain moves or a new half bath is added. Our plumbing installation work covers new drain and supply runs, and the toilet is set at the end.
If you only need the fixture swapped or repaired, our toilet repair and installation visit handles the bowl, the supply and the flange check in one trip. We also work in Piqua, where you would call the Miami County plumbing office about permits, and in Botkins, where plumbing permits go through the Sidney-Shelby County Health Department.
Whatever the job, ask for the price before work starts. A toilet swap with a flange repair is a different job than a swap without one, and the price should say which you are getting.
Common questions
Do older Sidney homes often need a flange repair when a toilet is replaced?
The City of Sidney's plan estimates that roughly 30 percent or more of Sidney's housing was built before 1950, so older flanges are common. Check the flange before the new seal goes down, since a corroded or low flange is the usual surprise in an older house.
Do I need a permit to replace a toilet in Shelby County?
Anyone doing plumbing work in Shelby County needs a permit from the Sidney-Shelby County Health Department, and minor repair is exempt. Call 937-498-7249, describe your job and ask whether it is covered.
What is toilet rough-in?
It is the distance from the finished wall to the center of the drain. A toilet is made for a specific rough-in, and a mismatch means the bowl sits too close to the wall or too far out.
Can I reuse the wax ring?
No. A ring compresses when the toilet is set, and it does not seal reliably a second time. Use a new seal each time the bowl comes up.
Why does my new toilet rock?
The floor may be uneven, the flange may sit low or the bolts may be uneven. Shim the base, check the flange height and retighten evenly. A rocking toilet will eventually leak.
Can hard water damage a new toilet?
It does not harm the porcelain, but minerals can foul the fill valve and the flapper over time. The city's 2022 report listed about 113 ppm hardness, so plan on replacing those parts as they wear.