Important announcement: The new 2015 Dept. of Energy efficiency mandates will require higher Energy Factor (EF) ratings on virtually all residential gas, electric, oil and tankless gas water heaters. These changes will have an impact on how water heaters are manufactured, distributed and installed, affecting manufacturers, wholesalers, installers, and customers. It will increase product and installation costs. In some cases, the water heater will have to be re-located to operate properly, or decrease noise. While the operating cost of the new water heaters will be less because of their increased energy efficiency, it is likely that the maintenance costs will increase because of a more complex design, and the integrations of electronics, blowers, fans, condensers, etc. In some cases, the performance of the new water heater in terms of hot water deliverability will be less than the model which was replaced. Expect the units to be larger, also.