You install a two-piece toilet in three phases: First, you secure the toilet base to the floor, then you fasten the tank to the base, and finally, you connect the water supply to fill the toilet with water.
A one-piece toilet is installed in the same way as a two-piece unit except that it’s more cumbersome to handle. Because it’s all in one piece, however, the installation goes faster, because you don’t need to install pieces separately.
Carefully read the installation instructions packaged with the toilet and identify the parts and then follow these steps to install a new toilet:
Remove the rag in the flange hole in the floor.
Scrape up any old wax and debris from the flange and surrounding area.
Locate the closet bolts and turn the T-shaped head of each bolt so that it slips into the slot in the flange. Push the bolt into the slot and slide it into position so it’s parallel to the wall behind the toilet. Turn the bolt, so the head can’t be pulled out of the flange. Slide the plastic retainer washers down the threads to hold the bolts in place.
Turn the toilet upside down and rest it on a padded surface.
Locate the toilet horn, the short spout in the center of the toilet’s base. Place the wax ring and its sleeve onto the toilet horn and press it down firmly.
This wax ring fits around the toilet horn and compresses against the drain flange as you press it to the floor and then bolt it into place. The plastic spout must face up. You have a one-time shot with a wax ring, because after the ring is compressed, it won’t spring back. The key to a proper seal is to lower the toilet onto the flange without disturbing it.
Carefully lower the toilet base onto the flange by aligning the closet bolts with the holes in the toilet base.
Have another person on hand to line up the bolts with the holes in the base as you lower the toilet onto the floor. Keep the base level as you lower it to the floor.
Gently but firmly press the base down on the wax ring.
Put a carpenter’s level across the toilet base to assure that the bowl is level, and then place the washers and nuts on the bolts, using an adjustable wrench to tighten them.
Alternate side to side as you tighten the nuts, checking that the bowl is still level side to side and front to back. Be careful not to overtighten the bolts. You don’t want to tighten them so hard that they crack the base of the toilet.
Cover the bolts with the trim caps.
If the bolts are too long for the trim caps to cover them, shorten them with a hacksaw.
Install the flush mechanism (if necessary).
Most toilets come with the mechanism installed.
Turn the tank upside down and attach the rubber seal, called the spud washer, to the pipe that protrudes from the bottom of the tank.
Carefully turn the tank right side up and center the spud washer over the water intake opening, which is at the back edge of the bowl in the toilet base.
Lower the tank to the back of the bowl, align the tank bolts and rubber washers with the holes in the tank, and insert the tank mounting bolts through the holes in the bowl.
On the toilet bowl’s underside, thread on the washers and nuts, tightening by hand at first and then with a large wrench.
Don’t overtighten. Be sure to turn the nut, not the bolt. Some toilet tanks have preinstalled mounting bolts, and others require that you preinstall the bolts. Follow the directions that come with the toilet.
Connect the riser (supply) tube and shut-off valve by fastening the coupling nut to the tank fitting and the compression fitting to the shut-off valve, first by hand, and then with a wrench.
Reinforced flexible tubes available in various lengths in white or braided stainless steel are very reliable and easier to install than standard plastic or chromed brass tubes.
Turn on the water supply at the stop valve to fill the tank and toilet with water, checking for any leaks and watching the toilet as it begins to fill with water.
The water flow should begin to slow and stop at the fill line marked inside the tank. Tighten connections only as needed to stop leaks.
Follow the manufacturer’s directions about adjusting the water level.
Some valves have a float arm that can be adjusted, and others have a setscrew to adjust.
Install the toilet seat by pushing the seat bolts through the holes in the toilet base and then holding the nuts on below while you tighten the bolts with a large screwdriver.