Toilet rocks after installation

Wax not fully compressed or flange low Loosen bolts; shim under base; retighten evenly; trim shims and caulk.

Water at base after flush

Wax seal failed or bolt overtightened Retighten bolts evenly; if still leaking, lift toilet and replace wax ring, reset without rocking.

Supply connection drips

Loose or cross-threaded connection Turn off valve; disconnect; reattach with tape or sealant per fitting type; hand-tight + ¼ turn.

All guides

BathroomIntermediate

Install New Toilet

Time

120–180 min

Steps

Pre-check

4 items

Skill

Intermediate

Scope

Install a new toilet from start to finish: remove the old unit, clean the flange, set a fresh wax ring and bolts, then secure the bowl and test for leaks.

Safety

Read before starting

Turn off water supply before starting. Toilets are heavy — use a helper to lift; lift with legs, not back. Plug flange opening immediately to limit sewer gas; wear rubber gloves when handling old wax; ensure ventilation when using sealants.

Pre-Check

4 items · complete before you start

New toilet matches rough-in distance (e.g. 10 in, 12 in) and fits space
Required
Supply valve behind toilet turns off and is accessible
Required
Wax ring (or wax-free seal per manufacturer), closet bolts, and supply line on hand
Required
Helper available for lifting old and new toilet
Required

0 / 27 complete

Shut Off and Empty

Turn off supply valve behind toilet clockwise
Flush to empty tank; sponge or towel remaining water from tank and bowl
Disconnect supply line at fill valve; have bucket and towels for residual water

Remove Old Toilet

Remove plastic caps over closet bolts; loosen nuts under base (may need to cut if corroded)
Rock toilet gently to break wax seal; do not pry with metal against porcelain
Lift toilet straight up and set on old towels or cardboard; get help — toilets are heavy
Stuff rag into drain opening immediately to limit sewer gas and debris

Clean Flange and Install New Bolts

Scrape old wax from flange and bowl horn completely with putty knife
Inspect flange: should be level with or slightly above finished floor; repair or reinforce if broken
Install new closet bolts in flange slots; orient so toilet base will align
For simple flange replacement: remove old flange hardware, clean pipe/floor, install compatible repair flange or replacement flange, and secure firmly to floor
If flange replacement requires subfloor or cast-iron work, stop and call a pro

Install Wax Ring and Set New Toilet

Place new wax ring on flange (tapered side down, centered over drain); do not compress before setting toilet
Remove rag from drain; align new toilet over bolts and lower straight down without rocking
Press down evenly to compress wax; sit on toilet to fully seat the seal
Check level; add shims under base if needed (trim flush, then caulk)

Secure and Connect

Hand-tighten washers and nuts on closet bolts; alternate sides and tighten gradually — do not overtighten or base can crack
Trim bolt tops if needed; install caps
Connect new supply line to fill valve and supply valve; hand-tight + ¼ turn
Turn water on slowly; let tank fill; check tank-to-bowl and supply connections for leaks

Test and Finish

Flush several times; confirm fill and shutoff; check base and flange for water
Caulk around base (leave back open per some codes to reveal leaks); clean squeeze-out
Dispose of old toilet per local rules

Code notes

Federal max flush volume: 1.28 gpf (EPACT 1992 amendments). Showerheads installed under 2024 IPC are limited to 2.0 gpm.
2024 IPC adds a multi-user toilet-door locking exception for active-shooter refuge — relevant to commercial fitouts.