Toilet repair

How to Replace a Toilet Closet Bolt Set

Direct answer: To replace a toilet closet bolt set, shut off the water, remove the toilet, install new closet bolts at the flange, then reset and tighten the toilet evenly so it does not rock.

Closet bolts are the fasteners that hold the toilet to the floor flange. If they are rusted, stripped, broken, or no longer holding the toilet firmly, replacing them usually means lifting the toilet and resetting it carefully.

Before you start: Match the replacement part to your exact toilet before ordering.

Last reviewed: 2026-04-05

Step-by-step fix

Step 1: Make sure the closet bolts are really the problem

  1. Check both sides at the toilet base for loose, missing, badly rusted, or spinning nuts and bolts.
  2. Gently try to rock the toilet near the bowl, not the tank. A toilet that shifts because the bolts cannot clamp it down is a good candidate for this repair.
  3. Look for signs that point to a bigger problem instead, like a soft floor, a cracked toilet base, or water damage around the flange area.

If it works: You have a clear reason to replace the closet bolt set and no obvious signs of a different failure.

If it doesn’t: If the toilet is stable and the bolts look intact, the problem may be old caulk, a bad wax seal, a damaged flange, or an uneven floor rather than the bolt set alone.

Stop if:
  • The toilet base is cracked.
  • The floor around the toilet feels soft or rotten.
  • The flange appears broken, badly corroded, or loose in the floor.

Step 2: Shut off water and remove the toilet

  1. Turn the shutoff valve clockwise until it stops.
  2. Flush the toilet and hold the handle down to drain as much water as possible.
  3. Use a sponge and bucket to remove the remaining water from the tank and bowl.
  4. Disconnect the water supply line from the tank or fill valve connection.
  5. Cut any caulk around the toilet base with a putty knife.
  6. Remove the nuts from the closet bolts, then lift the toilet straight up and set it on towels or cardboard.

If it works: The toilet is off the flange and the work area around the old closet bolts is exposed.

If it doesn’t: If the nuts are seized, apply steady pressure with a socket or wrench. If a bolt spins, you may need to cut the old hardware off carefully to free the toilet.

Stop if:
  • You cannot lift the toilet safely by yourself.
  • The flange breaks or pulls loose when the toilet is removed.

Step 3: Remove the old closet bolts and clean the flange area

  1. Pull the old closet bolts out of the flange slots.
  2. Scrape away old wax, debris, and loose rust so you can see the flange clearly.
  3. Wipe the flange area clean enough that the new bolts can slide into place and sit flat.
  4. Check that the flange slots are not cracked or worn so badly that the new bolts will not stay aligned.

If it works: The old hardware is out and the flange area is clean enough for the new closet bolt set.

If it doesn’t: If the new bolts will not seat in the flange slots, clean the slots again and recheck for hidden damage or deformation.

Stop if:
  • The flange slots are broken or too damaged to hold the new bolts securely.

Step 4: Install the new closet bolts in the flange

  1. Slide the new closet bolts into the flange slots, one on each side of the drain opening.
  2. Position the bolts so they are directly across from each other and centered for the toilet base holes.
  3. If your bolt set includes retaining washers or clips, install them to keep the bolts upright while you reset the toilet.
  4. Double-check that both bolts stand straight and are spaced evenly.

If it works: The new closet bolts are secure in the flange and ready for the toilet to be lowered onto them.

If it doesn’t: If the bolts keep tipping or shifting, reposition them and use the included retainers if provided so they stay upright during installation.

Stop if:
  • The bolts cannot be held in position because the flange is damaged or misshapen.

Step 5: Reset the toilet and tighten the new hardware evenly

  1. Lower the toilet straight down so the base holes pass over the new closet bolts without forcing them sideways.
  2. Press down gently to seat the toilet fully.
  3. Install washers and nuts on both closet bolts.
  4. Tighten each side a little at a time, alternating left and right so the toilet pulls down evenly.
  5. If the toilet rocks on the floor, add plastic shims where needed, then continue tightening just enough to hold the toilet firmly.
  6. Trim excess bolt length if needed and install the bolt caps if your set includes them.

If it works: The toilet sits flat, feels secure, and the new closet bolt set is tightened evenly without stressing the base.

If it doesn’t: If the toilet still rocks after light tightening and shimming, the floor may be uneven or the flange height may need correction before the toilet can be secured properly.

Stop if:
  • The toilet base starts to creak, flex, or show signs of cracking while tightening.
  • The toilet will not sit down evenly on the floor.

Step 6: Reconnect water and confirm the repair holds in real use

  1. Reconnect the water supply line and open the shutoff valve slowly.
  2. Let the tank fill, then flush several times while watching the base and supply connection for leaks.
  3. Sit on the toilet and shift your weight gently to confirm it no longer rocks.
  4. If you removed old caulk, recaulk the base after you are sure the toilet is stable and dry.

If it works: The toilet flushes normally, stays solid on the floor, and shows no leaking or movement after repeated use.

If it doesn’t: If the toilet still moves or leaks at the base, the reset likely needs to be redone and the flange, seal, or floor condition checked more closely.

Stop if:
  • Water leaks from the base after flushing.
  • The toilet still rocks noticeably after tightening and shimming.

Replacement Parts

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FAQ

Can I replace closet bolts without removing the toilet?

Usually no. Closet bolts sit under the toilet base, so the toilet normally has to be lifted off to replace them correctly.

Do loose closet bolts always mean the bolts are bad?

Not always. Loose bolts can also point to a broken flange, an uneven floor, or a toilet that was not reset properly. That is why checking for flange and floor damage first matters.

Why does the toilet still rock after I replaced the closet bolt set?

A new bolt set cannot fix an uneven floor, a damaged flange, or a poor reset. Light shimming may help, but persistent rocking usually means there is another issue under the toilet.

Should I tighten the nuts as much as possible to stop movement?

No. Tighten them evenly and only enough to hold the toilet firmly. Overtightening can crack the porcelain base.

Do I need anything besides the closet bolt set when I remove the toilet?

In many cases, yes. Since the toilet is coming off, many homeowners also replace the seal before resetting the toilet so they do not have to pull it again soon.