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Toilets 101

Whether you're saving water or fixing a leaky flapper, understanding how a toilet works and how to fix it is essential. The following information will give you a basic understanding and some troubleshooting tips on standard toilets.

How a Toilet Flushes

A standard gravity flush toilet has three basic working parts:

The Flush Lever & Chain - Opens the flush valve.
The Flush Valve & Flapper - Controls the flow of water from the tank to the bowl.
The Fill Valve - Controls the flow of fresh water into the tank.

  • When the tank lever is pressed, it lifts the flapper/tank ball by a chain.

  • This opens the flush valve and releases water through the rim, into the bowl.

  • From the bowl, gravity siphons the existing bowl water down the trapway.

  • Once the tank is empty, the flapper/tank ball drops back onto the flush valve seat, and the fill valve triggers a refill of fresh water into the tank.

  • The fill valve float rises inside the tank with the level of the water, until the pre-set refill level is reached, closing the fill valve.

Replacing a Toilet

Replacing a 3.5 gallon tank toilet with a 1.6 gallon tank toilet can save up to 350 gallons of water per week!

Installation of a toilet is a simple to complete project for any do-it-yourselfer. In addition to the tank and bowl, you'll also need:

1. A bolt set to affix the bowl to the floor/floor flange.

2. A wax ring to seal the opening between the bottom of the bowl and the flange.

  • We suggest a urethane core wax ring with a rubber boot. "Waxless" rings are also available.
  • Be sure the wax ring is seated securely and level on the bowl before placement. This will prevent any leaks after installation.

3. A supply line to connect the fresh water supply valve in the wall to the bottom of the tank.

  • Be sure not to over-tighten the supply line connection under the tank. These are typically a plastic connection, and hand-tightening should be adequate.
  • It is very important not to over-tighten the bolts that affix the bowl to the flange/floor, as well as the bolts between the tank and the bowl. Over-tightening on either can cause the china to crack or break.

Repairing a Toilet

Repairing a leaking toilet can save up to 100 gallons per week!

Before beginning any repair, you should turn off the water supply, and flush the toilet twice. This will empty the tank and bowl of water, and make it easier to access working parts.



Elliott's Recommendation


Flush Lever & Chain

This is typically a wear item, and not an item that causes a toilet to not perform, or to “run”. Check the flush lever arm to make sure it is not warped, broken. Check the chain to make sure that it is not too short or too long, and that it is not being obstructed by other parts inside the tank.

Elliott's Recommendation:

Replace the flush lever & chain.


Flush Valve & Flapper

When the flapper cannot create a tight seal against the flush valve, water leaks from the tank into the bowl. This can be caused by warped, cracked or damaged flappers. If you have to jiggle the handle to get the water to turn off after a flush, you will likely need to replace the flapper. If there is damage to the flush valve itself, i.e. damage to the round portion of the valve at the bottom center of the tank, water can leak out of the tank, even around a flapper in good condition, and in these cases, the valve and flapper will both need to be replaced. This is the most common toilet repair problem, and the simplest to correct.

Elliott's Recommendation:

Replace the flush valve and/or the flush valve flapper.


Fill Valve

Sometimes, extended use, as well as corrosion caused by chemical cleaners, can cause the shaft of the fill valve to either crack or fail. There is an overflow tube in the tank that catches and disperses into the tank overflow water. If the crack worsens, and the fill valve breaks away, it can cause the tank to overflow, and create flooding damage to property.

Elliott's Recommendation:

Replace the fill valve. There are several to choose from including ones with a vertical float and those with a horizontal float arm and float ball.

Flush Valve Seal

At the point where the tank seats against the bowl, there is a rubber seal, that can sometimes harden and crack, causing a leak from the tank, and causing water to escape to the floor.

Elliott's Recommendation:

Replace the tank-to-bowl washer.


Wax Ring

A failing wax ring can allow water to leak from the base of the toilet, and create water damage to the floor.

Elliott's Recommendation:

Replace the wax ring with either a urethane core wax ring, or a waxless ring between the toilet bowl and the floor flange.


Bolt Set

The toilet bowl bolts to the plumbing pipe through holes in the china at the base, and attaches to a plastic or metal flange that is glued to the end of the drain pipe under the floor. These bolts can sometimes rust and eventually break, causing leaks. It is a good idea to inspect them periodically, and to go ahead and replace them when the wax ring is replaced.

Elliott's Recommendation:

Replace the bolt set if broken, stripped, or if you are replacing the wax ring.

Note: Be sure not to over-tighten the supply line connection under the tank. These are typically a plastic connection, and hand-tightening should be adequate.

Adding Power to Low-Flow Toilets

  • If you have a float-arm flush valve, you can adjust the water level inside the tank by bending the float arm up or down slightly. This will change when the valve shuts off and how much water fills the tank.

  • Higher-quality flush valves are more rigid, and some come with a counter-weight that will leave the flush valve open longer, and allow the tank to completely empty so that the flush action lasts longer.

  • Some toilets are available with vacuum-assisted flush systems, which provide for more rapid water movement from the tank via air pressure, using the same 1.6 gallons of water!