Dual flush toilets are a favorite choice for people who want or need to conserve water but are worried about the functionality of many low flow toilets. According to Lowes, dual flush toilets can reduce water consumption by 60 to 80 percent compared to older high-volume toilets. While dual flush models can make a big difference in water consumption, they aren't without their problems. Knowing the potential disadvantages of a dual flush toilet can help homeowners make the correct decisions about their bathroom remodel.
According to Ask John Eakes, dual flush toilets and other flow models often clog, especially when they're installed on sewage systems that weren't designed for them. This problem is most common with siphon flush toilets installed in bathrooms that don't see much use, such as a guest bedroom. Wash-down flush toilets may require more cleaning but tend not to clog as often. Dual flush toilets of all kinds work well when they're installed in bathrooms that see a lot of use as the more frequent flushing prevents waste material from building up in the drain pipe.
Dual flush toilets cost more than traditional single flush toilets, due in large part to the lower demand for this style. As of 2010 and according to Green Home Guide, dual flush toilets start at around $175, compared to single flush toilets that cost less than $100. Fortunately, manufacturer competition and increased demand for effective, water-conservative toilets is slowly bringing dual flush models down closer to the price of more conventional toilets. Dual flush toilets also save water over time, resulting in a lower monthly water bill. It can take some time for this savings to pay for the initial difference in fixture cost though.
According to Lowes, dual flush toilet models often require more cleaning and are more difficult to clean than standard single flush models. These toilets retain less water in the bowl, which may result in an increase in dirtiness. It's also necessary to ensure that the water holes along the rims don't clog as this can decrease the toilet's ability to function.
Newer residential construction takes the needs of low-flush toilets into account, but dual flush models are not always compatible with older homes built when high-flush toilets were the norm. In addition, older plumbing may have developed sags, dips and other problems that prevent a dual flush toilet from working. Homeowners concerned about the compatibility of their plumbing should talk to an experienced professional before choosing a dual flush toilet.