Which statement is FALSE with respect to electric water heaters?

The statement indicating that the upper element usually comes on first is incorrect because, in standard electric water heater operation, the upper heating element is not automatically activated first; instead, it is dependent on the temperature of the water and the specific control settings of the heater. Typically, when a demand for hot water arises, both heating elements may engage to maintain the desired temperature. The upper element is known to have priority in terms of being engaged for heating purposes, but it won't always activate first based solely on its position.

The other statements are accurate in describing the operations of electric water heaters. Most water heaters indeed come equipped with two heating elements to provide efficient heating. The priority of the upper element means that if there is a demand for hot water, the upper element will primarily engage to heat the water at the top of the tank first, which is generally where hotter water is needed first for fixtures like sinks and showers. Lastly, it can be challenging to determine if one of the heating elements is burned out without specific testing equipment because both elements can fail without external signs, leading to inefficiencies or complete failure in heating.