Gerber Plumbing Fixtures LLC’s Maxwell Dual Flush is the company’s latest high-efficiency toilet (HET). According to the EPA, using a HET product (in place of a standard 1.6 gallon per flush ...

In our tests of single- and dual-flush toilets ... As their name implies, these toilets have a flush valve that relies on gravity. Water drops from the tank into the bowl to move waste down ...

Dual-flush toilets usually have a mechanical valve with a rubber seal in the cistern that opens to allow water to flow when flushed. That rubber seal can rapidly deteriorate, says Tucker.