Water heating is the second-largest energy cost for U.S. households. But you can save with a more efficient water heater, Consumer Reports explains.

“While contractors will still be able to install non-condensing commercial water heaters until the supply runs out, they will eventually have to switch to condensing water heaters,” Tarbert said.

Condensing water heaters will use the heat from the exhaust gas it produces (non-condensing models also produce exhaust gas) to heat incoming cold water, generally making them more energy efficient.