How to Install a Toilet: A Step-by-Step Guide

Replacing an old toilet with a new one can be easier than you think. Whether your current toilet is malfunctioning, you want to upgrade for style or water efficiency, or you’re dealing with a broken flange, knowing how to install a toilet is a valuable skill. Below is a detailed guide for removing the old toilet, preparing the new one, and making sure the installation goes smoothly.

1. Gather Your Tools and Materials

• New toilet (bowl and tank)
• Wax ring (possibly a double-thick ring if your flange sits below floor level)
• New toilet bolts (preferably 5/16-inch)
• Adjustable wrench or socket set
• Screwdriver
• Needle-nose pliers
• Wet/dry vacuum
• Towels or a rag
• Personal protective equipment (gloves and eye protection)
• Shims (if the floor is uneven)

2. Turn Off the Water Supply

1. Locate the shut-off valve on the wall behind or near the toilet. Turn the knob clockwise until it stops.
2. Flush the toilet to remove as much water as possible from the tank.
3. Use a wet/dry vacuum or sponge to remove leftover water in the bowl and tank.

3. Disconnect the Existing Toilet

1. Unplug any electrical bidet seat if applicable.
2. Using an adjustable wrench or pliers, remove the flexible supply line from the toilet tank. Place a rag or small container beneath it to catch any drips.
3. Unscrew the nuts on the toilet bolts at the floor. If they’re corroded or stuck, apply penetrating oil or carefully cut them off.

4. Remove the Old Toilet

1. Carefully rock the toilet bowl side to side to break the seal of the old wax ring.
2. Lift the toilet straight up. If it’s heavy or you have back concerns, ask for help.
3. Set it aside on a piece of cardboard to avoid wax getting on the floor.
4. Look into the flange (the pipe opening in the floor) and remove any leftover wax or debris. Inspect the flange for damage or corrosion.

5. Inspect or Replace the Flange

Check the flange to ensure it’s not cracked or lifting from the floor. If you see signs of weakness (rusted metal ring, hairline cracks, or separation from the floor), you may need to repair or replace the flange before installing your new toilet.

6. Prepare the New Wax Ring and Bolts

1. Remove the new wax ring from its box. If the flange is set too low, opt for a thicker wax ring or add a second ring.
2. Place the new toilet bolts into the flange slots, ensuring they’re aligned in a straight line for easier placement of the toilet.

7. Position the Toilet Over the Flange

1. Gently lower the new toilet over the flange, aiming the holes at the base of the toilet onto the bolts. It’s often easier to pick up the bowl from the sides near the rim for a steady grip.
2. Once the toilet is in place, press down slightly to seat it on the wax ring. The wax forms the watertight seal between the toilet and sewer line.

8. Secure the Toilet to the Floor

1. Add washers and nuts on the bolts. Tighten by hand first, then use a wrench in small increments—alternating between sides—to avoid cracking the porcelain.
2. Check if the toilet wobbles. If it does, insert shims around the base where needed to keep it level. Trim off excess shims so they don’t show.

9. Attach the Tank (If Not Pre-Assembled)

1. Install the flush valve and fill valve (if not already installed). Some toilets include these factory-mounted.
2. Secure tank-to-bowl bolts and rubber washers according to the manufacturer’s instructions. Make sure the tank rests on any rubber grommets or pads that prevent direct porcelain-to-porcelain contact.
3. Tighten the bolts evenly, checking that the tank is level. Over-tightening can crack the porcelain.

10. Connect the Water Supply

1. Reattach the flexible supply line to the fill valve under the toilet tank. Ensure the connection is snug but avoid over-tightening.
2. Slowly open the shut-off valve. Listen for any water leaks at the supply line or around the base of the toilet.

11. Adjust the Water Level and Flush

1. Once the tank fills, check the water level. Typically, it should be about an inch below the top of the overflow tube.
2. Test-flush to confirm the toilet is working properly and check for leaks around the base or at the supply line. Adjust the fill valve if needed to raise or lower the water level.

12. Trim Bolts and Add Caps

1. If your new toilet bolts protrude too far above the nuts, use a small hacksaw or bolt cutter to trim them.
2. Snap on the decorative caps for a clean finish.

13. Final Steps

1. If you prefer a cleaner look or extra stability, you can run a thin bead of caulk around the toilet base—leave a gap at the back for leak detection.
2. Install or reattach the seat. Some toilets come with a seat included, while others require a separate purchase.

Conclusion

Replacing a toilet doesn’t require specialized tools or advanced plumbing skills. With proper preparation—cleaning the flange, choosing the right wax ring, and ensuring bolts are secure—you can achieve a leak-free installation. Always double-check the floor for wobble, confirm the water level, and inspect for leaks after your first few flushes. A successfully installed toilet can serve you well for years to come.