water pouring from brown wooden bucket

4 Most Efficient Water Heaters

Originally contributed by • last updated 5/19/2021

Jainath Ponnala

Picking out a new hot water heater is a serious commitment. You’re going to be stuck with this machine for at least the next decade, so you want something that’s going to work, and work well.

Depending on what kind of energy source you use and whether or not you want to go tankless, this decision can be pretty tricky.

It’s one thing to understand what kind of water heater you want. There are great options for every type. But there are also other things to consider, like what size would work best for your household. And of course, you’ll also want to keep energy efficiency in mind.

On the plus side, nearly all hot water heaters on the market right now are energy efficient. Some work better than others, though, and may be a better bang for your buck.

Follow along here, and you’ll see some great options for the most common types of hot water heaters on the market.


Most Energy Efficient Electric Tank

Rheem Performance Platinum 50 Gal. Hybrid High Efficiency Electric Tank Heater

The Rheem Performance Platinum high efficiency heater is a really great option for anyone in the market for an electric tank hot water heater. It’s a hybrid, which is part of the reason why it’s so energy efficient.

Its size makes it perfect for a larger family, or for people who like to take a shower while the dishwasher is running.

The fun thing about this particular model is the fact that it has Wi-Fi capabilities. Though you have to purchase the Wi-Fi controls separately, it means you can fully integrate this model into a smart home.

And with a 10 year warranty, you’re going to be happy with this hot water heater for a long time. With a brand like Rheem, you know you’re getting something really good.


Most Energy Efficient Electric Tankless

EcoSmart ECO 11 Electric Tankless Water Heater

If you prefer tankless, one really great option is the EcoSmart Eco 11 tankless heater. Because it doesn’t have a tank, it’s going to be a more energy efficient option.

Since the hot water in tank heaters has to constantly keep warm, the heater will periodically turn on to heat whatever’s in the tank. Tankless heaters heat water on demand, meaning there's no stored water to keep at a consistent temperature.

This small, but powerful model keeps you comfortable with continuous hot water. It has an easy temperature control, meaning you can hit the sweet spot for for your baths or dishwashing every time.

This model also boasts a lifetime warranty. You won’t ever have to worry about water heater repairs for the its entire lifetime (which can be pretty long considering it’s tankless).


Most Energy Efficient Gas Tank

A.O. Smith Signature Premier 40-Gallon Short Natural Gas Water Heater

A.O. Smith

This A.O. Smith gas tank water heater is highly efficient. Natural gas heaters already tend to be more efficient than their electric counterparts, because they use gas rather than electricity.

This means they cost more upfront, but you’ll definitely see the savings down the road. Additionally, gas water heaters work even when the power is out.

This hot water heater has the ability to heat up to 65 gallons in the span of an hour. This is great for families, or people who just really, really like hot water.

With its 12 year warranty, you will be able to enjoy this highly efficient gas heater for a long time. And its Low NOx rating means you won’t have a huge impact on the environment, either. It’s overall a really great option for natural gas lovers.


Most Energy Efficient Gas Tankless

Rinnai RUC98iN Ultra Series Indoor Natural Gas Tankless Water Heater

When it comes to tankless gas water heaters, this Rinnai model is a really great energy efficient option. It has an Ultra Low NOx rating, meaning its emission levels are even lower than the A.O. Smith model above. Add the fact that it’s tankless, and that's a lot of energy saved.

A tankless hot water heater like this one would be good for smaller households, since the fact that it doesn’t have a tank does mean it’ll have less hot water to go around at any given time.

So if multiple showers are happening at the same time on weekday mornings, things coulf get chilly, but it will make up for that in the fact that the hot water you do get is consistent. 

This model has a warranty that will last for up to 12 years, which is a lot. It’s definitely going to be a bit more expensive up front, but it’ll be worth it in the long run.

What Does Energy Efficient Mean?

Energy efficiency refers to the amount of energy input versus the output of a hot water heater. Essentially, you’re looking at how much hot water the heater produces, as well as how much energy it takes to do so.

A really energy efficient hot water heater will be one that saves you money on your monthly energy bills. Though they are generally more expensive upfront, you can see upwards of several thousands of dollars saved on your bills over time. 

Not only that, but energy efficiency is better for the environment, since it means using less electricity or gas overall. That may not be on the front of everyone’s minds when purchasing a new hot water heater, but it’s definitely an added bonus.