To install a new toilet seal, shut off the water, empty the tank and bowl, unbolt the toilet and lift it off the floor flange. Scrape away the old wax, set a new wax ring on the flange or on the toilet horn, and press the toilet down straight and level. Then tighten the closet bolts evenly, reconnect the supply line and test for leaks. A careful first-timer needs about an hour and a helper for the lift.
The job is simple on a sound floor and flange. It becomes a plumber's job when the flange is broken, the floor is soft or the leak has been running for a while.
Rule out other leaks first
Water at the base is not always the wax ring. A sweating tank, a loose supply line or a leaking tank bolt can drip down the bowl and pool at the floor. Dry everything with a towel, put a dry sheet of toilet paper around the base and flush twice. If the paper stays dry but the tank bottom or supply connection is wet, you are looking at a toilet repair and not a seal problem.
Also check the shutoff valve. A valve that drips at the stem or will not close is a fixture-level repair, similar to a faucet repair, and you may want to replace it before you lift the toilet.
Tools and materials
Gather everything before you shut the water off, because the open drain is a good place to be calm and not hunting for a tool.
- New wax ring, or a wax-free seal sized for your drain, plus a new set of closet bolts.
- Adjustable wrench, a putty knife and a bucket.
- Sponge, old towels and a wet-dry vacuum or large cup to empty the bowl.
- Rubber gloves, safety glasses and a rag or stuffing to plug the drain.
- A helper, because a toilet is awkward and heavy.
Replacing the seal, one stage at a time
Work slowly. A seal that is pressed down crooked will leak again, even if the part is new.
Shut off the water and empty the toilet
Turn the supply valve clockwise, flush to drain the tank, and sponge out what remains. Disconnect the supply line and keep a bucket under it.Remove the toilet
Pop the bolt caps and loosen the nuts. Rock the toilet gently to break the old seal, then lift straight up with a helper and set it on towels or cardboard.Plug the drain and scrape the flange
Stuff a rag in the pipe so sewer gas stays out and nothing falls in. Scrape every bit of old wax from the flange with a putty knife.Inspect the flange
The flange should be solid and sit flush with or slightly above the finished floor. Cracks, rust or missing bolt slots mean a repair ring or replacement is needed first.Set the new seal
Place the wax ring on the flange, or on the horn under the toilet, with the cone facing down. Install the new closet bolts upright in their slots.Lower the toilet straight down
Line the bolts up with the holes and set the bowl down in one motion. Press down evenly with your weight and do not twist or rock it afterward.Tighten gradually and test
Add washers and nuts, tightening each side a little at a time. Stop when the bowl is firm and does not rock. Reconnect water, flush several times and look for leaks.
Flange and floor problems: fix at home or call a plumber
The flange is the ring on the floor that holds the toilet. Most failures that come back after a new seal trace to a bad flange or a bad floor.
| What you find | What it means | Who should handle it |
|---|---|---|
| Flange sits slightly below the floor | A thicker seal or a flange spacer may close the gap | Careful DIY if the flange is sound |
| Cracked plastic or rusted metal flange | The toilet has nothing solid to bolt to | Licensed plumber, since repair involves the drain pipe |
| Soft, dark or spongy floor | Long-term leak has damaged the subfloor | Plumber and a carpenter, before reinstalling |
| Toilet still rocks after tightening | Uneven floor or bolts that are too long | DIY with plastic shims, caulk the base after |
| Seal keeps failing within months | A slow drain, flange height or an overtightened bowl | Plumber, to check the drain and venting |
A bowl that cracks from overtightening is a common mistake. Snug is enough.
Safety and cleanup you should not skip
Wear gloves and keep the bathroom ventilated. Wastewater carries bacteria, and an open drain releases sewer gas. Do not use a flame or lighter near the open pipe.
Lift with your legs and ask a second person to help. A full-size toilet can weigh 60 to 100 pounds and the porcelain chips easily. Set it on an old towel rather than leaning it against a wall.
Disinfect the floor, tools and your boots afterward. If the old wax was wet, black or smelled foul, assume the leak ran a while and check the floor and ceiling below for damage. The standard to follow is the installation sheet that comes with the new wax ring or toilet.
When to stop and call a plumber
Stop the repair if the flange is broken, the floor gives under pressure or the drain pipe is cracked below the flange. Those are structural problems, and a new wax ring will not hold. Call a licensed plumber for flange replacement or any work that opens the drain beyond the toilet.
Call as well if the toilet leaks after a correct installation, if several fixtures gurgle or back up, or if you see water through the ceiling below. Water that keeps coming can mean the drain is partly blocked, and a blocked line sends the pressure back at the seal. A neighbor in Quincy or Braintree with the same trouble would hear the same advice.
Milton, MA specifics: older bathrooms and local rules
Source type: Town of Milton Housing Production Plan, Mass.gov Plumbers and Gas Fitters fact sheet
Milton homes have a median age of 71 years, and 46.8 percent date to 1939 or earlier. Bathrooms in houses that old have often been remodeled in layers, with a newer toilet set over an old cast iron or lead-bend flange, or on a floor that was raised with new tile. Check flange height and condition every time, because those older connections are where repair jobs hide.
Massachusetts does not require a permit for minor repairs such as fixing a leaky faucet or clearing a blocked drain. Resetting the same toilet on a new wax ring is generally a small repair, though the inspector has the final say. Replacing or relocating a fixture, valve or piping is different and does need a permit pulled by a licensed plumber, so if your project grows into moving the toilet, ask the Milton plumbing inspector first.
If you are unsure whether you need a licensed plumber, the state keeps a license lookup on its eLIPSE portal, and the Board can be reached at 617-727-9952. Work that does need a permit must be done by a master or journeyman plumber licensed by the state.
Questions readers ask about this topic
A properly seated ring can last for the life of the toilet. Rings usually fail because the toilet moved, the flange sits too low or the seal was pressed on crooked. Replace it any time you lift the toilet.
Both work. Wax is cheap and forgiving when the flange height is right. Rubber or foam wax-free seals can be reused if you need to lift the toilet again and often handle small height gaps. Pick the one that matches your flange height.
No. Once compressed, the wax cannot reseal evenly, and a reused ring is a common reason for a second leak. Always scrape the old wax off and fit a new one, even if you only moved the toilet an inch.
The floor may be uneven or the bolts too long. Use plastic shims under the base on the low side, tighten evenly, trim long bolts and run a thin bead of caulk around the base once it is stable.
Not for minor repairs like this one. The state requires a permit when plumbing is installed, altered, removed or replaced, and only licensed plumbers can pull it. Replacing the toilet itself or relocating it needs one. Ask the Milton plumbing inspector if you are unsure.
Look at flange height after any tile work, because added flooring can leave it too low. Check whether the flange is metal that has rusted through, and press the floor around it for softness. If it flexes or the ring is cracked, have a plumber replace it.
Rather talk it through? Call and ask a plumber.
(617) 752-0573