Posted: August 17, 2026
A typical tank-style water heater should last about 10 years before you begin to notice a reduction in performance. With good maintenance, they can last even longer. So it may have been a while since you last shopped for a water heater or given much thought to efficiency ratings.
Until recently, the rating information was inconsistent, so it was hard to compare brands. The Department of Energy has introduced a more streamlined system of rating standards that makes it much easier for you to understand water heater efficiency ratings.
Now, there’s one standard for testing and for sharing the information with customers like you. It’s known as Uniform Energy Factor, or UEF. Here’s what you need to know.
UEF: This number represents the overall efficiency of a water heater, that is, how much of the energy it uses goes to actually heating water and how much is wasted energy. The higher the UEF, the more efficient the water heater.
FHR/FHD: This stands for First Hour Rating or First Hour Delivery. It represents the amount of hot water a water heater model can produce in the first hour of operation. This lets you see the difference between very high-efficiency and more moderately efficient equipment. For example, a highly efficient water heater with a 40-gallon tank might be able to produce 80 gallons of hot water in an hour. In contrast, a water heater with an 80-gallon tank but a less powerful heating system might not produce more than 80 gallons of hot water, and it would deliver less than that in the next hour because it would need to heat the water refilling the tank.
GPM: Gallons per minute tells you how much hot water a tankless water heater will produce.
Since water heating can contribute to about 30% of your energy costs, finding an energy-efficient water heater can really help keep your costs more manageable. There are several factors to consider, such as the size of your home, how many people are in your household, and how many bathrooms, sinks, showers, and appliances that use hot water you have.
Of course, any new water heater will likely be more efficient than an older model. And if you have a tank-style system and want to stick with that, there are plenty of high-efficiency water heaters you can choose from.
Tankless water heaters offer several advantages over storage-type water heaters. Tankless water heaters save energy by instantly heating water when you need it, rather than keeping a large tank hot all the time. As a result, you can enjoy virtually unlimited hot water while seeing savings of up to 40%. They also last twice as long, or longer, than a tank-style water heater.
For super-efficient water heating, you should consider an electric heat pump water heating system. It can provide some of the lowest-cost, most eco-friendly hot water possible.
The experts at Roberts can help. We sell, install, and service all types of efficient propane water heaters. We’ll help you understand your options and show you the pros and cons of each to help you find the most efficient water heater for your home and your lifestyle.
Contact us for more information today.
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