Replacing a toilet drain can be a fundamental part of a toilet replacement, particularly if the fittings and fixtures are very old or decayed. This can certainly be the case in piping that is very old or is compromised for some reason.
Most are comprised of PVC piping, a very tough form of plastic that is used in piping, and has been for many years. It is not, however, indestructible and does require replacement for a variety of reasons. Some are relocating the placement of the toilet and are using an offset drain, or it may get damaged in the removal of the toilet. Here you will find the information you will need in undertaking the project.
Step 1 - Remove the Toilet
Start by removing the toilet. Shut off the water supply and disconnect the hose from the tank. Flush the toilet to remove as much water from the tank and stool as possible. Use a plunger to plunge the remaining water from the stool. Loosen and remove the nuts that secure the tank to the stool, and lift off the tank. Carefully lay the tank on a towel or blanket.
Next, loosen and remove the nuts for the anchor bolts holding the stool to the floor. Lift the stool off the bolts and set it on a blanket as well. Remove the wax ring. This should expose the drain piping.
Step 2 - Remove the Existing Drain
Start by attempting to remove the existing drain by gently rotating it clockwise. If the PVC glue is old, the drain may be able to be rotated and pulled out. If you can not remove the drain this way, examine the drain to identify where the fittings are. You should try not to damage the joints, as this will result in even more PVC being replaced. If not, use the cutting blade with the dremel to cut around the damaged or worn section of the PVC, and remove the section of PVC.
Step 3 - Install the New Drain
Once the old drain is removed, dry fit the new drain to ensure that all components do not need additional modification to reinstall the toilet. If needed, replace additional PVC fittings until the desired angle and height of the drain is achieved. Once confident of the fit, apply purple PVC glue to all insertions on the PVC and make your connections.
Step 4 - Reinstall the Toilet
Install the new wax ring. Reinstall the toilet in the reverse order that it was removed. Do not over tighten the nuts on stool or tank as this can cause the porcelain to crack, which will necessitate the replacement of the stool, tank, or both. Reconnect the water supply, and make sure to use plumbers tape to ensure a watertight seal. Once everything is reconnected, turn the water on and observe through several flushes to make sure there are no leaks.