Replacing Toilets

Home » Replacing Toilets

Installing a Toilet – the Other Half of the Job

As we said earlier, it doesn’t happen often but toilets do crack or break. More often the seal around the waste pipe will fail allowing water and waste to leak onto the floor or into the ceiling below. Obviously, it’s not a problem that can be ignored.


Replacing the toilet entirely or reseating the existing toilet with a new seal are identical projects except for the need to carefully measure for a replacement fixture.  Measurements are done from the wall to the center of one of the floor bolts; rear ones if there are four.  Compare this to the distance from the mounting holes to the back of the toilet you want to buy.  The usual wall-to-bolt distance is 12″ but an inch either way is still considered standard.  If you have to go with a non-standard size expect it to be more expensive and perhaps require a special order.

To replace or reinstall the existing toilet you will also need a wax ring and new closet (floor) bolts. You may also have to purchase a new seat separately.

Toilets are heavy and cumbersome so it is best to take the old one out in two pieces. Disconnect the water supply and remove the tank as we outlined in the last article and sponge out the remaining water in the bowl.

If there is caulk around the toilet base, cut through it with a utility knife.  Twist off the decorative caps from the closet bolts and remove the nuts or cut the bolts with a hacksaw.  Rock the toilet side to side to break the wax seal and remove the toilet.  If you are reinstalling it place it on newspapers or old rags, otherwise carry it straight out of the house.  Remove the closet bolts by sliding them to the wide end of the slot and stuff a rag into the waste pipe to keep sewer gas out of the house.

Now comes the icky part.  It is important to get all of the old wax off of the flange for the toilet to seat properly.  Scrape off the old stuff with a putty knife.  A little trick is to use the inside of a plastic grocery bag to wipe the wax off of the putty knife and hold it for disposal. Your hands never touch the mess.  After all wax is removed clean the area with a disinfectant or bleach solution.

Slide the new bolts into the flange with the ends pointing straight up.

Turn the toilet upside down on the floor.  If you are reinstalling, clean any wax off of the waste horn and disinfect it.   Place the new wax ring (warmed to room temperature) over the horn with the tapered end down.  Remove the rag from the waste pipe, turn the toilet right side up and position it onto the bolts and the flange.  Put the washers and nuts on the bolts but do not tighten.  Make sure that the toilet is sitting both square and straight and gently press it down into the wax ring with a rocking motion.  Tighten the nuts on the closet bolts a little bit at a time, alternating between or among them to evenly distribute the pressure.  Do not over-tighten or attempt to make the toilet absolutely flush with the floor – there will be a slight gap which can be sealed with a silicone caulk.  Put the decorative caps on the bolt ends.

Install the tank as in the previously instructions and reconnect the water supply.  Flush and check for leaks.

Scroll to Top