Water heaters have become an indispensable part of your home, in charge of your comfort and relaxation.
Since we have to invest money in a unit, most of us want to get the most efficient water heater.
You will have what you ask for. Below are 6 excellent units you need.
Most efficient electric water heater
- EcoSmart ECO 11 Electric Tankless Water Heater – Best overall
- Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater – Runner up
- EcoSmart ECO 27 Electric Tankless Water Heater – Best for cold northern climate
- Stiebel Eltron 24 Plus Tempra, Tankless Water Heater – Premium Choice
Most efficient propane water heater
- Takagi T-KJr2-IN-LP Indoor Tankless Water Heater – Best overall
- Eccotemp i12-LP water heater, 4 GPM, Black – Budget-friendly option
- Rinnai RL Model Tankless Hot Water Heater – High Capacity
Most efficient electric water heater
EcoSmart ECO 11 Electric Tankless Water Heater – Best overall
Pros
- Lifetime warranty
- Easy to install
- Easy to manage
- Great from small houses
Cons
- Only suitable for climates where the water temperature is 67F or above
What I love about EcoSmart Eco 11. Being a tankless water heater, the unit requires no ventilation system, which significantly reduces the amount of installation cost. The water comes immediately and continuously, adding comfort and convenience to your life.
This unit is certainly small and compact. You can place it almost anywhere in the house. When it comes to efficiency, the rating is 99.8%, which saves the electricity bills up to 60%. No stand-by, no wasted energy.
Another the great news for EcoSmart Eco 11’s users, this beast comes with a lifetime warranty. However, it is only applied if you have the heater installed professionally. Another drawback of this heater is the suitability to use in cold climate. It is certainly only compatible with moderate climates.
Product Specifications
| Energy efficiency | 99.8% |
| kW | 13 |
| Voltage | 240 |
| Max Amperage | 57 A |
| Required breaker(s) | 1 x 60 AMP |
| Min. required wire size & number of runs | 1 x 6 AWG |
| Min. flow to activate unit | 0.25 GPM
|
| Output water temp. range | 80°F – 140°F |
| Dimensions | 11.5″ x 8″ x 3.75″
|
| Highlight Features | Patented Self Modulating Technology and design, 99.8-percent energy-efficient, cut down on heat loss, saving you up to 50% in water heating |
EcoSmart ECO 11 Electric Tankless Water Heater offers a second-to-none value to small homes in a moderate climate. If this heater matches your requirements, don’t hesitate to buy one.
Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater – Runner up
Pros
- Easy to install
- Energy efficient
- Small and lightweight
- On-demand hot water
- Cost-effective
Cons
- Best for a single point of use
The second runner-up Rheem offers its charms when it comes to heating water.
It is indeed small and lightweight. Since the unit doesn’t take up space, you can easily find a spot in the bathroom or under the sink. The Rheem RTEX-13 features a LED display and knob to adjust water heat as you wish.
It is 99.8% efficient. It also comes with a water-saver shower head too. Compared to normal tank water heaters, this unit is a cost-effective option. At the end of the month, your electricity bill stays the same.
Some tankless water heaters can’t supply continuous hot water, but that isn’t the case with Rheem. No pre-heating and no leftover hot water after use.
The cons? This unit is small enough to accommodate a single point of use. So if you want to have hot water in the bathroom and kitchen at the same time, this machine isn’t for you.
Product Specifications
| Energy efficiency | 99.8% |
| kW | 13 |
| Voltage | 240 V |
| Max Amperage | 54 A |
| Required breaker(s) | 1x [email protected] breaker |
| Min. required wire size & number of runs | 6 AWG recommended wire size |
| Min. flow to activate unit | 0.3 GPM |
| Output water temp. range | 20°F – 100°F |
| Dimensions | 4 x 9 x 13 inches |
| Highlight Features | External adjustable digital thermostatic control with LED display (+/1 degree accuracy, durable Copper immersion two heating elements, simple installation |
Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater is an absolute choice for a single point of use. Smart, effective and affordable, it is a must-have at home.
EcoSmart ECO 27 Electric Tankless Water Heater – Best for cold northern climate
Pros
- Lifetime warranty
- Self-modulating technology and design
- Easy to manage
- Easy to maintain
- A reliable source of hot water
Cons
- Installation is quite difficult
Looking for a suitable heating unit for your house? EcoSmart Eco 27 could be a good choice. This model is large enough to heat 3 gallons of water per minute. It can provide hot water simultaneously for 2 points of use.
Its capacity is amazing. You can run 4 showers and a sink at the same time without hot water shortage. Plus, it can handle the incoming water temperature as low as 37 degrees F, which is ideal for the cold climate in the north.
The unit features a digital temperature control that allows you to set the water temperature according to your liking. It also offers a lifetime warranty for those who have it installed professionally. And you should because the installation process is tedious.
Product Specifications
| Energy efficiency | 50% |
| kW | 27 |
| Voltage | 240 V |
| Max Amperage | 113 A |
| Required breaker(s) | 3 x 40 Amp Double Pole |
| Min. required wire size & number of runs | 8 required wire |
| Min. flow to activate unit | 0.3 GPM |
| Output water temp. range | 80F – 140F |
| Dimensions | 17 x 17 x 3.6 inches |
| Highlight Features | Digital temperature control in 1-degree increments, copper and stainless components, compact size |
EcoSmart ECO 27 Electric Tankless Water Heater is a reliable source of hot water for people in the northern area. Its powerful capacity provides endless hot water and comfort.
Stiebel Eltron 24 Plus Tempra, Tankless Water Heater – Premium Choice
Pros
- Silent operation
- Digital display for better management
- The solid copper heating chamber
- Small and compact
- Energy efficient
- German quality
Cons
- Require professional installation
Want a bit of luxury in your house? Stiebel Eltron has everything to offer. It certainly catches people’s eyes by the sleek design. Adopting copper for the heating elements, this unit is made to last.
This is a German-quality unit, so no doubt it gives users the best experience when it comes to operation. It functions quietly. The intelligent self-modulating technology makes sure that this heater uses just enough water and saves energy.
It comes with a pre-set temperature buttons so that you can choose the water temperature before the shower. The showers are always hot thanks to the advanced flow control technology.
Anything to complain? It requires professional installation, which can make some people annoyed.
Product Specifications
| Energy efficiency | 99% |
| kW | 24 |
| Voltage | 240 V |
| Max Amperage | 150 Amp |
| Required breaker(s) | 2 x 50 Amp DP breakers |
| Min. required wire size & number of runs | 2 separate runs of 6-gauge copper wiring |
| Min. recommended household electric service | 208 Volt electric service |
| Min. flow to activate unit | 0.5 GPM |
| Output water temp. range | 68 to 140°F |
| Dimensions | 4.6 x 16.6 x 14.5 inches |
| Highlight Features | The sleek design saves space and no venting required, electronic switch activated for virtually silent operation, copper sheathed heating element housed in a copper cylinder |
The solid Stiebel Eltron 24 Plus Tempra, Tankless Water Heater offers premium experience and sleek design for extra comfort at home.
Most efficient propane water heater
Takagi T-KJr2-IN-LP Indoor Tankless Water Heater – Best overall
Pros
- CSA approved
- Great product functionality
- Easy to install
- A cost-effective purchase
- Durable
- Quickly heats the water (20 seconds) and stays hot
Cons
- Require professional installation (warranty)
If you prefer a propane water heater, this tankless unit from Takagi is the best overall option for you.
It comes with a bunch of safety features including freeze, surge protection, overheat and troubleshooting diagnostic codes. It can handle 2 points of use without fail. The water is heated within 20 seconds and stays hot until you stop.
The Takagi’s flame size varies to accommodate different water flow. It, therefore, uses less gas and saves energy.
How about the cons? The warranty specifically states that the unit needs to be installed with professional help.
Product Specifications
| Energy efficiency | N/A |
| Maximum BTUs | 140,000 |
| Minimum BTUs | 19,500 |
| Voltage | AC 120V |
| Max Amperage | N/A |
| Min. flow to activate unit | 0.4 GPM |
| max flow rate | 6.6 GPM |
| Output water temp. range | 99-167°F |
| Dimensions | 20.25 x 13.75 x 7.75 inches |
| Highlight Features | Include freeze, overheat, surge protection, and troubleshooting diagnostic codes |
Takagi T-KJr2-IN-LP Indoor Tankless Water Heater is an affordable and durable propane unit. It is safe to use and stays very durable.
Eccotemp i12-LP water heater, 4 GPM, Black – Budget-friendly option
Pros
- LED display
- Sleek black design
- Safety protections included
- Solid construction
- Versatile
Cons
- May not suitable for cold climate
Eccotemp i12-LP is a combination of great design and affordable price. Its sleek design is perfect for a small, shiny bathroom. This little beast features automatic temperature controls and child lock technology for extra protection.
The touch screen with LCD shows water temperature and GPM flow. It is perfect for small houses, vacation cabins, and cottages.
The unit is small but it indeed is solid. The efficiency rating is about 79%, which is enough to save your electricity bills at the end of the month. The Eccotemp is probably not the best choice for those in cold climate.
Product Specifications
| Energy efficiency | 79% |
| Maximum BTUs | 25,000 |
| Minimum BTUs | 80,000 |
| Voltage | 110V |
| Max Amperage | 1.07 Amps |
| Min. flow to activate unit | 0.6 GPM |
| Max flow rate | 4.8 GPM |
| Output water temp. range | 35 -77 F |
| Dimensions | 17.00″ x 29.00″ x 11.00″ |
| Highlight Features | Sleek, modern design with black tempered glass front panel, fully automatic temperature controls with an energy-saving mode and child lock technology |
Eccotemp i12-LP water heater, 4 GPM, Black is a budget-friendly option for a small family. Its sleek design will bring additional decorative benefit to your house.
Rinnai RL Model Tankless Hot Water Heater – High Capacity
Pros
- Safe to use
- Endless hot water
- High capacity
- Quiet operation
- Amazing technology
Cons
- Take time to install
- Some complaint about the warranty
When it comes to high capacity, Rinai RL is my top pick. It can provide hot water for the whole house with a flow rate of 9.4 GPM.
Compared to other gas tankless heat water, this unit is super safe to use since it uses outside air for combustion. It provides hot water until you turn the unit off. The hot water will arrive a few seconds later than in tank water heaters but it stays strong and hot.
This unit comes with advanced technologies and high-tech elements such as combustion fan, pc board to manage the gas and water flow. It functions quietly too.
Rinnai offers 12 years of warranty on heat exchangers, but you need to make sure you install it with professional help. The installation is quite tedious and takes some time too.
Product Specifications
| Energy efficiency | 82% |
| Maximum BTUs | 180,000 |
| Minimum BTUs | 10,300 |
| Voltage | 115 volts |
| Max Amperage | |
| Min. flow to activate unit | |
| Max flow rate | 9.4 GPM |
| Output water temp. range | 35 -127 F |
| Dimensions | 14 x 10 x 23 inches |
| Highlight Features | Up to 9.4 GPM hot water flow rate, Circ-Logic technology, compact, interior-mount |
Looking for a high capacity water heater to run the house? Rinnai RL Model Tankless Hot Water Heater is hand-down the best catch.
How to choose the most efficient water heater (buying guide)
Types of water heaters
First thing first, never go shopping with an empty mind. You need to know which options are available on the table.
There are 5 types of water heaters.
- Tank water heaters store hot water in a ready reservoir.
- Tankless water heaters heat water directly.
- Heat pump water heaters move heat around to generate hot water.
- Solar water heaters use solar energy to heat water.
- Tankless coil and indirect models come with a home heating system.
Size
The size of a water heater also indicates its efficiency. How many points of use do you want to cover? How many people share the hot water system?
Think carefully about the answer and choose the size that can cover the need of everyone in your house. If you live in a big family, a properly sized heater is needed.
However, if only one or two people use hot water, a small budget-friendly unit is all that you need.
Energy efficiency
Check the energy efficiency of the unit you intend to buy. This way you can maximize the energy used without compromising electricity bills.
Costs
How much are you willing to spend on a water heater. It is worth to estimate the operating cost of a water heater.
This way, you will have an overview of how much you have to spend on a unit annually, thus making a realistic and reasonable choice.
Who makes the most efficient water heater?
Not many manufacturers can make efficient water heaters at the user-friendly price. These 6 brands are exceptional. They invest in new technology, advanced safety features, and cost-effective models.
Their products incorporate experience, science, technology and customer-minded manufacturing process.
The most efficient propane water heater brands:
- Takagi
- Eccotemp
- Rinnai
The most efficient electric tankless water heater brands:
- EcoSmart
- Rheem
- Stiebel Eltron
FAQs
Should I replace my water heater before it fails?
Don’t just wait for the catastrophe. You should look for signs to replace your heater before it creates a mess.
An average lifespan of a heater ranges from 8 to 12 years. If your unit is approaching the old age, check for indicators of a new one. It could be the rattling noise that you hear every time it runs, or discolored water and even leaks.
Is a tankless water heater worth it?
Tankless water heaters are the ultimate choice for those who want a long-term solution for their hot water demand.
These units are famous for the continuous supply of hot water. They heat water instantly, allowing you to indulge in luxury hot baths without delay. What’s more, tankless models offer a longer lifespan. Some can stay as long as 12 years or more.
How long should a hot water tank last?
The durability of a water tank depends on many factors. A well-maintained tank can last up to 15 years. The construction and maintenance can significantly affect the longevity of a heater.
Most tank water heaters can only survive between 8 to 12 years.
How much does it cost to have someone install a water heater?
The cost to install a water heater professionally varies from types and regions. You have to pay between $1000 to $3000 for a water heater installation.
How often should you flush your water heater?
There is not a fixed period to flush your water heater. However, most manufacturers and experts recommend that flushing should be done once a year.
The bottom line
The quest for the most efficient water heater could be daunting if you don’t know where to start. Hopefully, this piece of writing has given you a glimpse of what options are available in the market and how you can start shopping for your heating unit.
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I’m James J. Decker, a hobbyist and DIYs and also a big of home improvement and gardening tools. I immensely enjoy how these amazing products improve productivity and efficiency, and allow me to do jobs for which I would’ve otherwise needed professional help.
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