Motorists along California's highway 405 now have something else to look at: a billboard displaying the millions of dollars wasted each day by California homes and businesses that use traditional hot water tanks.

According to tankless water heater manufacturer Rinnai—the company responsible for the billboard—Californians with traditional hot water tanks are wasting approximately $5.1 million a day to heat their water.

“California has always been a trend-setting state when it comes to adopting energy-efficient technologies,” says Ervin Cash, Rinnai's senior vice president. “Our hope is that the nearly 200,000 drivers who go past our billboard each day will recognize the positive economic impact of going tankless and decide to make the move to tankless water heating.”

Rinnai says the billboard is meant to educate residents that the 13 million single-family homes in California waste about $1.9 billion a year, or more than $3,500 a minute. Traditional tanks store a limited amount of water and constantly heat and reheat it, whether or not it is needed. A tankless system only heats water that runs through the unit's heat exchanger, thus saving money and energy.

Learn more about markets featured in this article: Bakersfield, CA, Fresno, CA, Los Angeles, CA.