Toilet Tips

The newest generation of high-efficiency toilets (HETs) are 20 percent more efficient than current federal standards. HETs not only take water efficiency to higher levels, they are frequently capable of flushing more waste. HETs are currently offered by all major fixture manufacturers.

The revolutionary improvements in toilet performance technology and testing can virtually guarantee user satisfaction. The most revered measure of toilet performance is the Maximum Performance (MaP) ratings which realistically evaluate the maximum amount of solid waste specific toilet models can consistently flush. At minimum, a toilet should be able to reliably flush at least 250 grams of solid waste and 24 sheets of toilet paper. The MaP test rates toilets’ flushing abilities up to 1,000 grams.

Surprisingly, there is very little correlation between the amount of water flushed and the effectiveness of a toilet. In testing, some 3.5 gallon per flush toilets cannot consistently flush 250 grams of waste, while some 1.1 gallon toilets reliably flush a full 1,000 grams.

Historically, toilets have relied upon a rubber flapper at the bottom of the tank as a means to dam water into the tank, then release it quickly into the bowl when the toilet was flushed. These flappers typically wear out within a few years, but many homeowners neglect to replace them. Studies have found that about 20 percent of all toilets have a flapper that fails to seal the tank outlet, allowing thousands of gallons to be invisibly lost down the sewer. When selecting a new toilet, consider the value of flapperless designs which may improve water savings for the long term.

HET’s can be dual-flush, pressure-assisted, or gravity flush. Each technology has pros and cons.

Dual-flush HETs

Commonplace in other first-world nations, these toilets have two-flush controls: one for liquid waste and the other for solids. When used properly, the overall average flush volume is typically around 1.28 gallons per flush (gpf). A variety of quality manufacturers make dual-flush toilets, some meeting the 1,000 gram test maximum. Some dual-flush toilets are lever operated, requiring the user to raise the lever for a small flush and depress the lever for a full flush. Others have two distinct buttons to select the flush. With the lever style dual-flush toilets, there is a possibility that users will not be conscientous enough to lift the lever when a small flush will suffice, thus resulting in higher than expected water use. The button style design requires a conscious decision.

Pressure-assisted HETs

These toilets employ a closed vessel inside the tank. When pressurized water enters the vessel, air is compressed at the top. When the water is released, the air expands rapidly, creating a high-velocity jet of water that pushes the waste through the trap. Eight major manufacturers make pressure-assisted HETs that flush with just 1.1 gallons and are capable of consistently disposing of 500 to 1,000 grams in a single flush. Although pressurized units have become quieter, some people object to the brief, but noisy flush. A benefit of pressurized units is that they are flapperless.

Gravity flush HETs

The new generation of gravity flush high-efficiency toilets typically have enlarged flappers and waste trapways. Through computer modeling and extensive testing, engineers have developed models with superior siphoning action to help pull the waste through the bowl. Gravity flush HETs are available that are capable of flushing up to 1,000 grams of solid waste. Gravity flush HETs use flappers and many of the flappers are proprietary, which may make it difficult to find replacements at a neighborhood hardware store.