How to Drain a Toilet

A fully-installed toilet

 Somporn Siripitakdet / Getty Images

The work of repairing a toilet or replacing it with a new model often requires that the toilet bowl and tank be completely drained of water. The question of how to fully drain a toilet perplexes many homeowners, and with good reason. This fixture has water flowing through it all the time and is connected to a very large drain pipe, but it's not built with a system for getting all of the water out of the bowl—or even the tank. More than one homeowner has been surprised when he unbolts the toilet from the floor and tries to move it, and is greeted with a small amount of water spilling out of the toilet bowl or tank onto the floor.

When emptying a toilet bowl, it's especially important to get all of the water out of the trap (a cavity just beyond the hole in the bottom of the bowl that contains water at all times). You can usually empty the trap through the toilet bowl, but be aware that there might be residual water inside the base. The best method for completely draining the tank and bowl sometimes depends on whether or not the toilet is clogged. And you may need to combine several methods in order to get the toilet completely empty of water.

Turn off the Water Valve and Flush

The first step to draining a toilet is to turn off the water supply and flush. This removes most of the water from the tank and the bowl. However, you should do this only if the toilet is not clogged. If it is clogged, move directly to plunging (see below).

  1. Locate the shutoff valve (a small valve, often with a football-shaped handle). It will be located where the water supply pipe emerges from the wall or floor and will usually be connected to a supply tube running to the toilet's supply valve, mounted on the bottom left side of the tank.
  2. Turn the handle of this shutoff valve clockwise until it stops turning.
  3. Flush the toilet, holding down the flush lever until the tank is as empty as possible. 
  4. The small amount of water left in the bottom of the tank can be removed with sponging. Sponging can also work to remove any remaining water in the toilet bowl.

Note: Be aware that old shutoff valves sometimes stop functioning correctly. There is a chance that the toilet's shutoff valve will no longer fully shut off the water supply. If this is the case, you may need to shut off the main water supply valve for the entire house before you drain the toilet.

Plunge out the Water

Plunging a toilet

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Plunging helps remove the water from the toilet bowl whether the drain is clogged or not. The plunging motion pushes the water out of the bowl, through the trap, and down the drain. This may be the best method to use if the toilet drain is clogged and you cannot flush the water from the tank without overflowing the bowl.

  1. After shutting off the water supply valve, place the flange of a toilet plunger (also called a closet plunger) firmly into the drain hole in the bottom of the toilet bowl. Plunge with an up-and-down motion to get most of the water out of the bowl. This should also force out any clog in the drain.
  2. Flush the toilet to empty the tank. If the clog has been removed, the water should flow freely through the bowl and down the drain, leaving you with only the small amount of water in the drain trap.
  3. Again use the toilet plunger to try and force most of the remaining water in the bowl down into the drain line. There is likely to be a small amount of water left, both in the bottom of the tank and in the bottom of the bowl trap, but this remaining water can be removed by sponging (see below). 

Siphon out the Water

Siphoning requires a short, flexible hose that you don't mind getting dirty. You'll probably want to wear rubber gloves because you'll have to dip one hand into the toilet water. This method is effective only if there is no paper or other material in the bowl. This method can also be used to drain all water out of the tank.

  1. Fill up the hose completely with water from a sink or tub, then plug the openings at both ends of the thumb with your thumbs so that no water escapes (this allows air in and breaks the siphon). 
  2. Set one end of the hose into the toilet bowl (or the tank), and direct the other end into a bucket so that the bucket end is lower than the water surface in the bowl.
  3. Release your thumbs from both ends of the hose. The water will begin draining and will continue as long as you keep the bowl end submerged in water and keep the bucket end lower than the bowl.

Bail out the Water

A cup or small bowl works for bailing water out of a toilet bowl or tank. Even the cap from a can of hairspray or spray paint can reach low enough to get the majority of the water. You'll need to reach into the very bottom of the bowl in order to empty the water from the toilet's trap.

Sponge out the Water

After all other methods are complete, there will very likely be a small amount of water in the toilet bowl or in the very bottom of the toilet tank. A large, absorbent sponge will remove this residual water from a toilet bowl and tank surprisingly quickly. Wear rubber gloves and squeeze the sponged water into a bucket as you absorb it from the tank or bowl.

Vacuum Out the Water

A wet-dry vac makes quick work of draining a toilet but is recommended only if the toilet water is clean. Make sure to remove the filter in the vacuum (to prepare it for "wet" mode) and be careful not to overfill the vacuum bin with water. You don't want to slosh through the house carrying a heavy vacuum bin full of toilet water.