6 Most Efficient Water Heaters of 2021

Last update: 2021-10-25

Every household needs a water heater. You’ll have a choice among many options - tank or tankless, electric or propane. In this article, I will address the advantages and disadvantages of each type. But first, let me recommend some good models.

Here are the most efficient water heaters you can buy in 2021:

  • Fast Heating (Electric Tank Water Heater): Camplux ME60 Mini Tank
  • Easy To Install (Electric Tankless Water Heater): Eemax EEM24027
  • Best For Hard Water (Electric Tankless Water Heater): Sio Green SIO14 v2
  • Durable (Propane Tankless Water Heater): Rinnai V65IN
  • Easy To Use (Propane Water Heater): Camplux Pro 1.58 GPM
  • Budget Choice (Propane Tankless Water Heater): Marey GA10LP
6 Most Efficient Water Heaters
Fast Heating
Camplux ME60 Mini Tank
  • Electric Tank Water Heater
Easy To Install
Eemax EEM24027
  • Electric Tankless Water Heater
Best For Hard Water
Sio Green SIO14 v2
  • Electric Tankless Water Heater
Durable
Rinnai V65IN
  • Propane Tankless Water Heater
Easy To Use
Camplux Pro 1.58 GPM
  • Propane Water Heater
Budget Choice
Marey GA10LP
  • Propane Tankless Water Heater

Electric Water Heater

Electric water heaters are the common choice as they are convenient. Compared to a propane water heater, you don’t have to worry about the gas running out.

Fast Heating (Electric Tank Water Heater): Camplux ME60 Mini Tank

Camplux ME60 Mini Tank
Camplux ME60 Mini Tank
9.8Outstanding
Pros
  • Built-in insulation foam for heat retention
  • High-Quality Built & Elegant Design
  • Easy to install with bracket included
  • UL Approval Safety & IPX24 Waterproof
  • Overheat protection & Freeze protection
Cons
  • Does not have a drain valve

Camplux ME60 is my first pick for the most efficient water heater. Being a mini-tank water heater with a maximum power level of 1440 watts, this Camplux ME60 heat water extremely fast. The temperature range is pretty wide, from 50-140°F (10-60°C). Moreover, it features a built-in insulation foam for better heat retention.

Camplux ME60 meets the UL Safety standards. Besides, it is rated IPX24 waterproof; it features overheat protection and freeze protection. In terms of safety features, I rate this heater highly.

Camplux ME60 has an elegant design with a high-quality built. There is also an indicator to let you know when the heater is on. The knob lets you adjust the output temperature. Moreover, as a tank water heater, Camplux ME60 is reasonable in price and pretty easy to install. The heater comes with a bracket for wall or floor mounted. Just simply tap the heater into the cold water line and install the water heater directly at the sink.

The only drawback of this heater, I would say, is that it lacks a drain valve. This causes some trouble when you want to drain it - you have to turn the whole heater over.

Camplux ME60 Mini Tank Specifications

Dimensions

15.8 x 21 x 15.5 inches

Tank Volume

6 gallons

Water Pressure Range

150 PSI

Temperature Range

50-140°F (10-60°C)

Highlight Features

Built-in insulation foam; UL Approval Safety; IPX24 Waterproof; Overheat protection; Freeze protection; A bracket included

Verdict

Camplux ME60 is a mini-tank water heater with a maximum power level of 1440 watts.

Easy To Install (Electric Tankless Water Heater): Eemax EEM24027

Eemax EEM24027
Eemax EEM24027
9.4Outstanding
Pros
  • Tankless water heater
  • Up to 27,000 watts
  • Instant, consistent and endless
  • Self-modulating technology
  • Digital temperature control
Cons
  • Takes a while for the hot water to reach around the house

Eemax EEM24027 is my first recommendation if you like a tankless water heater. A tankless water heater has a significant advantage over a tank water heater as it has higher energy efficiency. It has heating tubes; when you turn on the tap, the water goes through these tubes and being heated. So the hot water flow is consistent and endless.

Eemax EEM24027 features self-modulating technology, which self-adjusts energy consumption to reach the highest energy efficiency while maintaining fast and endless hot water. Moreover, it features digital temperature control, so you can easily adjust the temperature from 80°F to 140°F in increments of 1 degree F.

Eemax EEM24027 consumes up to 27,000 watts to heat the water. It heats 6.6 gallons of water from 77°F to 105°F per minute. However, since being a tankless water heater, it is not as fast as the Camplux ME60. It takes a while for the hot water to go around the house. This may be a drawback if you want fast hot water.

Eemax EEM24027 Specifications

Dimensions

17.0 x 17.0 x 3.8 inches

Tank Volume

Tankless

Water Pressure Range

80°F to 140°F

Temperature Range

Resident water pressure

Highlight Features

Self-modulating technology; Digital temperature control

Verdict

Eemax EEM24027 features self-modulating technology and digital temperature control.

Best For Hard Water (Electric Tankless Water Heater): Sio Green SIO14 v2

Sio Green SIO14 v2
Sio Green SIO14 v2
9Outstanding
Pros
  • Premium tankless choice
  • Patented technology - no coil metallic elements
  • Automatic Power Technology
  • No corrosion & No maintenance
  • 100% satisfaction or money back
Cons
  • Higher price than others

Sio Green SIO14 v2 is a premium tankless water heater, which ensures instant, consistent, and endless hot water for your house. This heater features a patented technology that contains no coil metallic elements, so the heater prevents corrosion, limescale deposit, and calcium buildup. Thanks to that, if you have to deal with hard water, which contains minerals like Calcite and Magnesium, this Sio Green SIO14 v2 is the choice for you.

Like the Eemax EEM24027, this Sio Green SIO14 v2 also features an automatic power technology for maximizing energy efficiency. Besides, you’ll be backed with a 100% satisfaction or money back policy within 30 days. So, although this heater costs much higher, you can buy it with confidence.

Sio Green SIO14 v2 Specifications

Dimensions

20 x 14 x 6 inches

Tank Volume

Tankless

Water Pressure Range

80°F to 140°F

Temperature Range

Resident water pressure

Highlight Features

No coil metallic elements; Automatic Power Technology; Digital temperature control

Verdict

Sio Green SIO14 v2 contains no coil metallic elements, so preventing calcium buildup.

Propane Water Heater

Propane Water Heaters have several advantages over Electric Water Heaters. First, propane is cheaper than electric, so the operation cost of a propane heater is much less than an electric heater. Second, propane heats faster than electric. Third, propane furnaces last longer than electric heat pumps.

Durable (Propane Tankless Water Heater): Rinnai V65IN

Rinnai V65IN
Rinnai V65IN
9Outstanding
Pros
  • Tankless heater for endless hot water
  • Up to 7.5 GPM hot water flow rate
  • There is an option of 9.4 GPM
  • Control-R 2.0 mobile app
  • Up to 10 years of warranty
Cons
  • Pretty high price

Rinnai V65IN is a propane tankless water heater. This is a good solution for endless hot water, for medium houses. Unlike other tankless heaters requiring a waiting time before getting your hot water, this Rinnai V65IN with the ThermaCirc360 technology recirculates hot water through the pipes, so you'll get your hot water faster.

Rinnai V65IN has a sleek, compact design, which is also easy to install and use. It is highly energy-efficient, which uses 40% less gas than other traditional tank heaters. You’ll have a 7.5 GPM of hot water flow rate. There is an option of 9.4 GPM - you can consider this if you need more hot water.

Rinnai V65IN features a smart WiFi monitoring technology, so you can monitor and adjust the heater through your smartphone. The temp range is from 98 to 140 degrees F. This is an exceptional feature that no other heater has.

This is a highly reliable and durable propane heater. You'll be backed with a 10-year warranty of the heat exchanger, a 5-year warranty of the part, a 1-year warranty of the labor. Moreover, every part of the heater is replicable so you can easily buy new components to replace the damaged old components.

Rinnai V65IN Specifications

Dimensions

14 x 9.3 x 26.9 inches

Tank Volume

Tankless

Water Pressure Range

Residential water pressure

Temperature Range

98°F - 140°F

Highlight Features

Control-R 2.0 mobile app; 10 years of warranty

Verdict

Rinnai V65IN is a propane tankless water with WiFi monitoring, ideal for medium houses.


Budget Choice (Propane Tankless Water Heater): Marey GA10LP

Marey GA10LP
Marey GA10LP
8.8Great
Pros
  • Much more affordable
  • Compact & Energy efficient
  • Easy to install and easy to use
  • Up to 3.1 GPM of hot water
  • 5-year warranty
Cons
  • Not showing temp in digital number

Marey GA10LP is my recommendation if you don’t want to spend too much on a water heater. This is also a propane tankless water heater, which provides you with endless hot water. However, since this heater does not feature a circulating pump, so you have to wait for several minutes for the hot water to reach all corners of the house.

Marey GA10LP is compact, lightweight, easy to use, and easy to install. It has high energy efficiency, which saves a lot of operating costs. It produces up to 3.1 GPM of hot water. You’ll have three knobs to adjust the heat level and the output flow.

Despite being an affordable product, this Marey GA10LP comes with a 5-year warranty. You can buy it with confidence. However, you won’t be able to see the current temp of the output water as it does not show the temp in the digital number.

Marey GA10LP Specifications

Dimensions

6.9 x 13.6 x 23.6 inches

Tank Volume

Tankless

Water Pressure Range

Residential water pressure

Temperature Range

Not showing

Highlight Features

5-year warranty

Verdict

Marey GA10LP is easy to install and easy to use - a basic and affordable heater.

How To Choose The Most Efficient Water Heater?

First, you need to choose between an electric one or a propane one. As said above, electric heaters are pretty convenient. However, propane heaters have a lower operation cost, heat faster, and are likely to last longer.

Then, you need to choose between a tank heater or a tankless heater. As said above, a tank heater is much lower in the upfront cost (the unit and installation cost); also, you’ll have hot water instantly as turning on the tap. When it comes to a tankless heater, you have to wait a while for the hot water to reach the tap; it also costs much higher when buying and installing a tankless heater. However, in the long run, a tankless heater uses less electricity than a tank heater, so be more energy efficient.

Which Brands Make The Most Efficient Water Heater?

Camplux

As the name has said, Camplux is an iconic brand that provides outdoor tools for an efficient outdoor lifestyle. Being in the business for over 18 years, Camplux has built a reputational brand on gas and electric heating solutions. They provide water heaters, camping stoves, RV appliances, gas fire pits, and other tools and accessories. When it comes to water heaters, Camplux has both tankless and tank models for camping and residential uses. You can trust in the quality of this brand.

Eemax

Eemax is another big name when it comes to hot water solutions. Their biggest advantage is the cutting-edge heating technology for tankless water heaters, which is both highly efficient and fast heating. Since being established in 1988, up to now, they have successfully built a world-wide reputational brand. Besides water heaters, Eemax also provides solutions for handwashing, residentially and commercially. This is my recommended brand for electric tankless water heaters.

Rinnai

If you are interested in propane water heaters, Rinnai is the to-go brand. Needless to introduce, Rinnai is one of the most worldwide recognized brands. People know Rinnai for its gas heaters, stoves, boilers, and other kitchen cooking tools. When it comes to Rinnai, you are assured of premium products that last for decades.

FAQs

Which type of water heater is most efficient?

In terms of energy efficiency, tankless heaters are better than tank heaters.

Is Rheem or AO Smith better?

Both are great brands. Rheem is known to have better products. However, AO Smith is known to have better services. So it depends on your preferences. Anyway, you won't go wrong with these two brands.

How often should you flush the water heater?

I highly recommend flushing the water heater every six months to avoid any rust or buildups.

How long do water heaters last?

Water heaters last very long as long as you maintain them regularly. You can expect a life span of from 10 to 15 years, or even longer.

What is the downside of a tankless water heater?

Two main downsides of a tankless water heater are: first, its upfront cost (the unit and installation cost) is pretty high; second, it takes a while for the hot water to reach every corner of your house, so you don't have instant hot water like a tank water heater.

Conclusion

Above are my six recommendations on the most efficient water heater. Also some comparison on the advantages and disadvantages of each type. I hope you find this article helpful.

Eugene Williams
Eugene Williams

Related Articles