Hot Water Heater Efficiency Guide

Energy Efficient Hot Water Heaters

When it comes to water heaters, many folks base their purchase on the water heater’s efficiency – and for good reason. According to, water heaters are the second highest energy consuming appliance in the home. That being said, it makes sense why homeowners would want to pay closer attention to how much energy they require in order to operate.

So, what exactly does it take to make a hot water heater energy efficient? Here are some things to look for:

  • EF Rating: This is the most important factor in determining efficiency. “EF” stands for “energy factor,” and the EF rating indicates just how efficient each unit is. To determine the water heater’s EF rating, you divide the amount of hot water produced by the amount of fuel used. The higher the  EF rating, the more efficient it is.
  • Energy Star: As you begin shopping for a new unit, you’ll notice that some may have a blue sticker that says “Energy Star.” This indicates that the product is Energy Star certified, which means that the United States Environmental Protection Agency (EPA) has certified the product as efficient. However, keep in mind that a water heater does not necessarily need to be Energy Star certified in order to be considered efficient.

Because these heaters require so much energy to function, installing an efficient water heater can significantly cut down energy costs in your home. An added bonus? You can get an tax credit by installing an Energy Star certified water heater in your home.

Are Tankless Water Heaters More Efficient?

Yes! Tankless hot water heaters are more efficient than traditional storage tank units and can provide you with plenty of hot water on demand. The good news is that the technology is constantly improving, and storage tank water heaters are becoming more efficient day by day. Storage tank units are also ideal if you have a large household, as they can supply more water than a tankless unit.

For more information on how to choose a tankless unit, check out our Tankless Water Heater Guide.

Energy Efficient Water Heaters

Water Heater ModelEF (Energy Factor) RatingEnergy Star
Rinnai RUR199i Condensing Tankless0.93Yes
Rinnai V75i Non-Condensing Tankless0.81No
Rinnai CU160i Sensei Commercial Condensing Tankless0.93Yes
Bradford White RG2PV75H6N Power VentNo
Bradford White RG2PV50T6N Power Vent0.70Yes
Bradford White RE2H50S6-1NCWT AeroTherm Heat Pump3.39Yes

Tankless Water Heaters

Rinnai TanklessRinnai RUR199i 9.8 GPM Sensei+ Condensing Tankless Hot Water Heater with Built-In Re-Circulation Pump

Designed for both residential and commercial use, the Rinnai RUR199I Tankless Water Heater provides 199,000 BTUs of power and a hot water flow rate of 0.26 – 9.8 GPM. Available in both natural gas and liquid propane, this unit can be used to power up to six fixtures at the same time — think shower, dishwasher, washing machine, etc. This makes it a great option for a family.


Rinnai V75i High Efficiency Non-Condensing, 7.5 GPM Tankless Hot Water Heater for Indoor Installation

The Rinnai V75i is another excellent efficient tankless water heater for residential use. Thanks to its 180,000 BTUs of power and a flow rate of 0.26 – 7.5 GPM, this unit is ideal for a home with two to three bathrooms. It can be used to operate up to four fixtures simultaneously.


Rinnai CU160i 8.0 GPM Sensei Commercial Condensing Tankless Hot Water Heater

If your commercial water heater could use an update, you’ll want to take a look at the Rinnai CU160i. This Energy Star certified water heater provides 97% thermal efficiency, which makes it one of the most efficient units we carry! Whether you’re a hotel or a restaurant, the Rinnai CU160i is an excellent option that supplies a hot water flow rate range of 0.26 – 8 GPM.


Power Vented Gas Tank Water Heaters

Bradford White 75 Gallon Storage TankBradford White RG2PV75H6N 75 Gallon, Power Vent Water Heater

If you’re in the market for an updated and efficient storage tank unit, the Bradford White RG2PV75H6N is a great choice. This energy efficient gas water heater features a 75 gallon tank and 76,000 BTUs of power, making it suitable for families of four or five. It features a 90° Recovery Rise of 82 minutes, which means that from the moment cold water enters the tank, it will take about an hour and 20 minutes to reach 90 degrees.


Bradford White RG2PV50T6N 50 Gallon, Power Vent Water Heater

The Bradford White RG2PV50T6N is another great power vented option. With a 50 gallon tank, this natural gas storage tank water heater is ideal for smaller families (think 2-4 people). A key detail of this unit that you’ll want to pay attention to is the Energy Factor (EF). This number indicates the unit’s efficiency – the higher the number, the more efficient the unit. The Bradford White RG2PV50T6N boasts an EF of 0.70, which makes it efficient for household use.


Electric Heat Pump Water Heaters

Bradford White RE2H50S6-1NCWT 50 Gallon AeroTherm Heat Pump Water Heater

If you’re in the market for an energy efficient electric water heater, the Bradford White RE2H50S6-1NCWT is one you won’t want to miss. It features a 90° Recovery Rise of only 21 minutes, making it another one of the most efficient units we offer! This unit is Energy Star qualified and features an EF rating of 3.39, making it extremely efficient.


Upgrade Today

Replacing your old unit for an energy efficient one will not only help ensure you have access to hot water when you need it, but it can also help you save money in the form of energy bill savings and tax credits. There are so many benefits of efficient water heaters, and we can’t wait for you to experience them. Shop our water heaters now to get started.

If you still have questions or concerns, please don’t hesitate to contact us. We’re here to help you find the best product for your household needs.

Mickey Luongo

Mickey is the resident heating and air conditioning expert with over 15 years of experience in the industry.

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