HomeCostGuideHow to Install a Toilet
Installing a toilet on an existing flange (not moving the plumbing) is a manageable weekend project if you work carefully through each step.
Updated May 2026 — written and reviewed by the HomeCostGuide editorial team
Steps
- 1
Shut off water and remove the old toilet
Turn off the supply valve, flush to empty the tank, disconnect the supply line, unbolt the base, and lift the old toilet off the flange.
- 2
Clean and inspect the flange
Scrape off the old wax ring, check the flange for cracks or damage, and confirm it sits at or slightly above the finished floor level.
- 3
Set new closet bolts and the wax ring
Insert new closet bolts into the flange slots, then place the new wax ring on the flange (or on the toilet outlet, depending on ring type).
- 4
Set the toilet
Lower the toilet straight down onto the bolts and press down firmly and evenly to seat the wax ring — don't rock it side to side.
- 5
Secure and check level
Hand-tighten the nuts onto the closet bolts in small increments, alternating sides, and check the toilet is level, shimming if needed.
- 6
Connect water and test
Attach the tank (if separate), connect the supply line, turn the water back on, and check carefully for leaks at the base and supply connection after flushing several times.
Safety notes
- Toilets are heavy and awkward — get help lifting if needed, and keep your back straight when lifting.
- Don't over-tighten closet bolts; the porcelain base can crack.
When to call a pro
If the flange is broken, sits below the finished floor, or you're relocating the toilet to a new spot, that's plumbing and flooring work best handled by a professional.
Frequently asked questions
Do I need a new wax ring even if the old one looks fine?+
Yes — always use a new wax ring when resetting or installing a toilet. It's inexpensive insurance against a slow leak at the base that can damage subflooring.
How do I know if my flange is the wrong height?+
The flange should sit at or slightly above the finished floor. If it's noticeably below, you'll need a flange extender kit rather than just a thicker wax ring.