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6 Most Efficient Gas Water Heaters of 2024

By Eugene WilliamsLast update: 2024-04-18

Having your home equipped with the most efficient gas water heater doesn’t mean you will have to sacrifice your enjoyment of unlimited hot water. Technologies have gone a long way. And it's now possible for you to get unlimited hot water with no fear of steep utility bills at the end of the month. Here are our picks:

Here are the most efficient gas water heaters you can buy in 2024:

  • Fast Heating (Indoor Gas Water Heater): FOGATTI FGD24IN
  • Easy To Install (Indoor Gas Water Heater): MAREY GA24CSANG
  • Highest Flow Rate (Indoor Gas Water Heater): Rinnai RU160In
  • Lowest Flow Rate (Portable Gas Water Heater): CAMPLUX ENJOY OUTDOOR LIFE AY132
  • Compact And Lightweight (Portable Gas Water Heater): GASLAND BE158B
  • Easy To Operate (Portable Gas Water Heater): GREATBEAR ‎MT55-R
6 Most Efficient Gas Water Heaters
Fast Heating
  • Indoor Gas Water Heater
Easy To Install
  • Indoor Gas Water Heater
Highest Flow Rate
Rinnai RU160In
  • Indoor Gas Water Heater
Lowest Flow Rate
  • Portable Gas Water Heater
Compact And Lightweight
  • Portable Gas Water Heater
Easy To Operate
  • Portable Gas Water Heater

Fast Heating: FOGATTI FGD24IN

  • Fast-heating – 170K BTU of power output & tankless design
  • Prevent excessive temperature in the summer - Micro-Frame Combustion Technology
  • Instructions need improvement

The FOGATTI FGD24IN gives you on-demand hot water in seconds, with superior temperature stability, and it even heats up faster than other tankless water heaters we tested.

The secret? The combination of a powerful motor and the world's most advanced technology.

This tankless water heater produces 170K BTU each hour.

Adopting the Micro-Frame Combustion Technology, it prevents the excessive temperature in the summer. Adding to its efficiency, the heat exchanger is built of oxygen-free copper.

This water heater is also reliable by meeting all quality requirements of CSA to be legally used in Canada and the US.

FOGATTI FGD24IN Specifications


26.2 x 17.1 x 7.3 inches

Maximum Operating Pressure

150 PSI

Maximum Power Output

170000 BTU

Highlight Features

170K BTU of power output & tankless design

Micro-Frame Combustion Technology

oxygen-free copper heat exchanger


Speaking of fast-heating capability, the FOGATTI FGD24IN is hard to beat.

Easy To Install: MAREY GA24CSANG

  • Easy to install
  • Dependable - DOE, UL, and CSA certified design
  • Able to match different positions – the modern LED touch-screen and elegant full-white design
  • No complaint

While all gas water heaters must be installed by a licensed electrician or plumber for quality and safety, there's no denying that the MAREY GA24CSANG is very easy to install. It takes a far shorter time to be completely installed than other counterparts, so you don't have to wait long to enjoy hot water.

The GA24CSANG meets all requirements of DOE, UL, and CSA. It's built with many safety features to reliably avoid freeze, flame failure, block, and overheating.

But what sets this unit apart is the LED touch-screen and elegant full-white design, so you don't have to try to hide it away.

MAREY GA24CSANG Specifications


7.3 x 17.1 x 26.2 inches

Maximum Power Output

170,000 BTU/hr

Highlight Features

DOE, UL, and CSA certified design

the modern LED touch-screen and elegant full-white design

Easy to install


The MAREY GA24CSANG is the easiest-to-install among the indoor gas water heaters we’ve found.

Highest Flow Rate: Rinnai RU160In

Rinnai RU160In
Rinnai RU160In
  • Offer unlimited on-demand hot water – 9GPM of the maximum flow rate
  • Highly energy-efficient - UEF rated design
  • Long-term durability, up to 20 years
  • High price
  • The fan is a bit noisy

Of all the indoor gas water heaters we tested, the Rinnai RU160In offers the highest flow rate, up to 9 GPM, for the most consistent stream. You'll never run out of hot water regardless of how often or how much you need it.

But that's not all.

This tankless water heater is UEF rated for high energy efficiency, which means it actually saves you from expensive water and power costs. It's also proven to last twice longer as other brands, typically up to 20 years.

While this unit offers hot water quickly, its Circ-Logic is compatible with an external pump to heat up faster when in need.

Rinnai RU160In Specifications


22.05 x 14.76 x 33.86 inches

Highlight Features

9 GPM of the maximum flow rate

UEF rated design


At up to 9 GPM, the Rinnai RU160In is our winner when it comes to the highest flow rate gas water heater.


  • Offer the lowest flow rate, 1.32 GPM
  • Versatile – 46.4℉ to 114.8℉ of water temperature ranges
  • Wish the shower head attachment was a little longer

The CAMPLUX ENJOY OUTDOOR LIFE AY132 is a rare gas water heater that actually offers a very low flow rate, typically 1.32 GPM.

Its two powerful D batteries offers on-demand hot water from 46.4℉ to 114.8℉ nearly in no time, which is versatile for many specific needs, and perfect for rural and off-grid areas.

Built with six-in-one protection and CSA approved, the unit works risk-free.



14.8 x 11.42 x 4.33 inches

Maximum Operating Pressure

3.0~110.0 PSI

Temperature Range

46.4℉ - 114.8℉

Maximum Power Output

28,000 BTU/hour

Highlight Features

1.32 GPM

two powerful D batteries

46.4℉ to 114.8℉ of water temperature ranges


Check out the CAMPLUX ENJOY OUTDOOR LIFE AY132 if you’re looking for an energy-efficient gas water heater with the lowest flow rate.

Compact And Lightweight: GASLAND BE158B

  • Compact & lightweight - 11.8 x 6.1 x 17.3 inches of dimensions & 15.36 pounds of weight
  • Powerful - up to 41K BTU per hour
  • 11.5% more energy-efficient than regular models - advanced combustion technology
  • A bit pricey

The GASLAND BE158B wins over other portable gas water heaters for its compactness and lightweight design, making it a shining contender for remote travel or off-grid camping.

For your information, this unit measures 11.8 x 6.1 x 17.3 inches and weighs just 15.36 pounds.

But don't get it wrong, the BE158B is a powerful performer. Its maximum power output is up to 41K BTU per hour, which is 30-40% more than our other picks. It also offers 1.58 GPM, so you won't run out of hot water.

Using advanced combustion technology, the BE158B optimizes gas consumption, helping you save up to 11.5% of energy--a lot more efficient than regular models.

GASLAND BE158B Specifications


11.8 x 6.1 x 17.3 inches

Maximum Operating Pressure

3.6-110 PSI

Maximum Power Output

41,000 BTU/Hr.

Highlight Features

11.8 x 6.1 x 17.3 inches

15.36 pounds

up to 41K BTU per hour


In need for an efficient portable gas water heater with compact and lightweight design? Don’t skip the GASLAND BE158B

Easy To Operate: GREATBEAR ‎MT55-R

  • Easy to operate - all-in-one designed setting knob
  • Simple readout – bright and clear LED screen
  • Low-maintenance - a dustproof plate and a windproof cover
  • No complaint

The GREATBEAR ‎MT55-R is an easy-to-install and easy-to-operate portable gas water heater that everyone can start with ease, even if you're just a beginner.

The installation process takes no further than 15 minutes to complete.

The all-in-one designed setting knob is user-friendly while the LED screen is bright and clear for easy readout. No learning curve at all.

Some other also-great features are a dustproof plate and a windproof cover to keep the unit long-lasting, efficient, and low-maintenance.

GREATBEAR ‎MT55-R Specifications


11.3 x 5.1 x 15.7 inches

Maximum Operating Pressure

2.5-110 PSI

Maximum Power Output

37000 BTU/hr.

Highlight Features

all-in-one designed setting knob

bright and clear LED screen

a dustproof plate and a windproof cover


The GREATBEAR ‎MT55-R is our pick for those who want an efficient, easy-to-operate portable gas water heater.

How To Choose The Most Efficient Gas Water Heater?

Tanked Or Tankless Gas Water Heater?

There are two common types of gas water heaters:

Tanked gas water heaters

This type includes an insulated water reservoir where water is heated to the desired temperature and accommodated until needed.

They are best for individuals who frequently draw water for multiple uses simultaneously, such as running a dishwasher and a shower at a time.

But take note that tanked gas water heaters are more cumbersome and complicated to install than the tankless. Besides, as their heating elements have to work constantly to maintain the on-demand water temperature, they might not be as energy-efficient as their counterparts.

Tankless gas water heaters

Understandably, this type of gas water heater is easier to install, and more efficient and space-saving than tanked models.

However, it offers a limit of GPM, which is just suitable for small families or individuals who don’t require a huge amount of hot water at the same time.

The GPM ranges of tankless gas water heaters are varied depending on inlet water temperatures. The colder the inlet water, the fewer the flow of hot water per minute.

Gallons Per Minute/ Water Tank Capacity

Gallons Per Minute

Consider the flow rate (GPM) if you choose to buy a tankless gas water heater. On the contrary, consider the water tank capacity if you choose to buy a tanked model.

The flow rate of a gas water heater indicates the amount of hot water it can provide in a minute. The higher the flow rate, the more hot water the water heater provides. Of course, its price tag will be up with the GPM.

For the majority of households, a 5-10 GPM tankless gas water heater is ideal.

Water Tank Capacity

Your go-to tank size depends on the number of people who will use the tanked gas water heater and the maximum hot water usage.

For example, if your family uses 80 gallons of hot water as the maximum, you should opt for a tanked gas water heater that features a reservoir no smaller than 80 gallons in capacity.

EF Rating

To maximize cost and energy savings, it’s important to check the EF (energy efficiency) rating of the gas water heater you’re about to purchase.

Energy efficiency rating was created by the US Department of Energy, aimed to help shoppers identify how energy-efficient a device is. Its scale ranges from 0.5 to 2. The higher the number, the more energy-efficient the device.

Which Brands Make The Most Efficient Gas Water Heater?


In the household appliance field, Fogatti is the global leading supplier of innovative and highly reliable tankless water heaters with the latest technology and features. Their safety-proven products help improve the lifestyle quality of customers.


When it comes to efficient tankless water heating solutions at competitive prices, Marey is hard to beat. They've been in the industry since 1955, known to offer unlimited on-demand hot water through their innovative lines of tankless water heaters.


Rinnai Corporation--a Japanese multinational company founded in 1920--is the favorite of worldwide homeowners and business owners than any other tankless water heater brand because of their top-notch quality, durability, and efficiency.

Fact: Rinnai are the 1st main tankless brand to produce in America.


Camplux is a brand dedicated to manufacturing portable gas tankless water heaters for cabins and campsites. They're the part of JAL group, a leading cooperation specializing in delivering easy and efficient outdoor solutions with over 18 years of expertise.

Camplux's products stand out for innovations, efficiency, and portability.


Is there a high efficiency water heater?

Yes, there is. Many water heaters are built to be 10-50% more energy-efficient than regular models, depending on the size of water pipes, placement, heater location, and family size.

In brief, high-efficiency water heaters save homeowners money on their monthly energy bills.

Are new gas water heaters more efficient?

Yes, they are.

New gas water heaters are more efficient than conventional gas storage models because they help decrease the excess heat loss.

Should I replace my 20-year-old water heater?

Yes, you should.

As a 20-year-old water heater is nearing the end of its lifespan, it’ll be more affordable to replace it rather than have a professional fix it.

Can a gas water heater last 25 years?

Yes, it can. But this doesn’t commonly happen. A gas tanked water heater typically lasts 8-12 years while a gas tankless model lasts around 20 years, if properly cared for.

What are the signs of a hot water tank going bad?

Below are common signs of a hot water tank going bad:

  • You have constantly hire a professional to repair it
  • Strange noises when the unit is operating
  • Your water heater doesn’t provide enough on-demand hot water
  • Water is discolored
  • Leakage problems happen


Selecting the most efficient gas water heater is no easy task with a wide array of options to choose from. First, you need to decide which type of gas water heater (tanked or tankless) will suit your home. Then, determine the amount of hot water you need at a time. Don’t forget to consider the EF rating.

Hopefully, our comprehensive review and buying guide will help you sort through the options to pick the right one for your needs.

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