Rear-outlet toilets flush waste out of the bowl through a backward-facing connection rather than a downward-facing one. These types of toilets are commonly used in Europe and the United Kingdom, where sewer plumbing pipes are usually fixed on the outside of houses. You can install a rear-outlet toilet on your own, if you have wall-mounted toilet plumbing fittings, without any specialised plumbing tools.
Apply silicone grease to the outside of the horizonal pipe surface sticking out of the wall. This will help you slip the bowl into position as well as help seal against leaks.
Move the bowl into position next to the sewer pipe. Slowly press the bowl toward the wall, slipping the sewer pipe into the opening at the rear of the bowl. Continue pushing until the pipe locks into place.
Lower the tank onto the back of the bowl. Line up the outlet in the bottom of the tank or cistern with the opening at the back of the bowl. Secure the tank to the bowl with the tank bolts.
Apply pipe thread compound to the threads on the inlet at the bottom of the tank.
Connect the cistern toilet supply tube or hose to the inlet on the bottom of the tank with the coupling. Tighten with a wrench.
Use the power drill with screwdriver attachment to secure the bowl to the floor with the bowl screws. Most bowls will have two places in the base of the bowl to hold the screws.
Turn on the water supply for the rear outlet toilet. After the tank fills, flush the toilet and check for leaks. Secure any screws or couplings, if needed.