10 Best Tankless Water Heater Reviews & Buying Guide

As the chilly weather sets in, there’s nothing more satisfying than stepping into a warm and invigorating shower. However, finding the perfect tankless water heater for your home can be a daunting task with so many options available in the market.

Fret not, for we have done the research for you and compiled a comprehensive list of the best tankless water heaters that will undoubtedly meet your needs. Whether you’re looking for energy efficiency, space-saving designs, or endless hot water supply, we’ve got you covered.

Invalid table id.

1. Rinnai RUC98iN (Best For Home Use)

This amazing water heater has immaculate and precise energy consumption which is always beneficial for the long run. It is indeed a top-notch product to have for your home with low NOx emission which makes it safe for children. 

2. EcoSmart ECO 27 (Best For Small Family)

The digital temperature control for the EcoSmart ECO 27 is a must-have for your small family. Well, it always gives you proper temperature intervals so that a family of 2-3 people can always have the best of the water heater.

3. Rheem RTEX-18 (Best For Single Use)

The Rheem RTEX-18 has an astonishing design and sleek body which can fit any corner of your bathroom wall. It has a decent flow rate of 4.4 GPM which makes the heater a good pick for personal use. You must have it if you are living alone.

4. Stiebel Eltron Tempra Plus 36 KW (Best For Commercial Use)

When you pick a heater for commercial use, you must think of a high flow rate and energy consumption. The Stiebel Eltron Tempra plus 36 KW is certainly a great pick in such perspectives. The electronic switch activation is a great advantage for hotel rooms. 

5. Takagi T-KJr2-IN-NG (Best For High Flow Rate)

If there is any occasion in your home, and you want to buy a proper water heater that will be connected with most of the faucets, the Takagi T-KJr2-IN-NG is a great option for you. The high flow rate ensures that you can get hot water through all the faucets at the same time. 

6. Takagi T-K4-OS-NG (Best Budget Buy)

The Takagi T-K4-OS-NG has all those features which you like to have in your home for personal and family use. The decent flow rate and the built-in freeze protection make sure that you can enjoy your time having a bath. 

7. Noritz NRC661-DV-NG (Best For Regular use)

Getting a water heater for your regular use must have two things- a decent flow rate and low NOx production. The Noritz NRC661-DV-NG immaculately passes all the tests which make it an ideal buy. The low energy consumption is just a gift with your heater. 

8. Rheem RTGH-95DVLN (Best For Water Conservation)

The Rheem RTGH-95DVLN masters the art of saving water with the help of smart technology. Hot start programming has instant heating technology that just saves your time and quickly ready for short use. 

9. TAKAGI TH3OSLP (Best For Big Family)

The TAKAGI TH3OSLP hot Water Heater has the most advanced thermistor in our list that actively works with instant heating. It takes just a minute to be ready and pouring hot water for your shower. It’s an ideal buy for a big family.

10. Stiebel Eltron Tempra Plus 24 kW (Best For Personal Use)

It is a great product when we consider for personal use mainly because of the low power consumption and self-modulation power technology. So it always keeps the heater off when you are not using it. 

Top 10 Tankless Water Heater Reviews

1. Rinnai RUC98iN Natural Gas Water Heater Review

This water heater is just the right product which you would want to take in your home when you want to use it regularly. Coming to the energy consumption of the product, we found that it has around 0.95 energy factor. So this means that even if you use the product for 4-5 hours in a day, it is cost-saving. 

Coming to the burn consumption, we found that the Rinnai RUC98iN Tankless Water Heater is around 152000-199000 BTU. This means that the burn rate is effectively higher. So it means that the product takes very little time to get heated up. One can roughly say that it takes around 1-2 minutes to completely heat the water inside. 

The heating capacity is quite decent for the product and it can easily heat the water up to 95-140 degrees Fahrenheit which can easily use natural gas propane. The product includes a concentric and PVC venting option. This PVC venting means that it has proper hot water and cool water ventilating system to prevent any type of overflow. Here is a detailed review of propane tankless water heaters.

The Product dimensions are just around 10 x 18.5 x 26 inches which means that the body is quite sleek and compact. So even if you fit the heater in any corner for your bathroom, you will still have some space left aside. 

Considering the gas emission from the product, it is a good choice for your home. It features Ultra-Low NOx emissions. Thus, the product also takes care of the environment around with making the air completely friendly and safe for children.

Specifications

Item Weight: 82 Pounds
Product Dimensions: 10 x 18.5 x 26 inches
Flow Rate: 9.8 GPM
Water Consumption: 9.8 Gallons
Warranty: 5 Years

Pros

Concentric or PVC Venting option
Up to 0.96 Energy Factor
Comes with a space-saving Design
Ultra-low NOx Emissions

Cons

Price is high

Final Verdict

The Rinnai RUC98iN Water Heater brings up a lot of innovation and fruitfulness to your regular use. We found the product to be smart and fast heating technology allows you to get better from the product. It is a bit expensive, but is also a must buy if you wish to get a proper product with several features.

Rinnai RUC98iN Ultra Series Indoor Natural Gas Tankless Water Heater, Twin Pipe
  • INDOOR installation only. Fuel Type: NATURAL GAS.
  • Concentric or PVC venting option
  • Up to 0.96 Energy Factor/Up to 0.92 Uniform Energy Factor
  • The space-saving design allows Indoor Installation type
  • Ultra low NOx emissions

2. EcoSmart ECO 27

If you are looking for a compact model with so many benefits, there can nothing be better than the EcoSmart ECO 27. The product has dimensions around 3.6 x 17 x 17 inches which means that the makers have particularly focused on the space-saving design. Apart from this, we also found that it is completely light in weight and just around 11 pounds.

The safety concerns of the heater are indeed remarkable. In fact, it includes a digital temperature control which allows you to control the hot water. This means that you can get a recording for every 1-degree interval for the temperature. So even if your heater is used for long hours and you fear about overheating, you can control the temperature easily with the valve.

Coming to the mechanism, the product uses complete electricity to power the ignition. But it also makes sure that there is not much energy lost. In fact, the EcoSmart ECO 27 comes with decent features to save up the water heating time of the product with the radiant heating technology. This decreases the electricity consumption for long usage. We have recently reviewed 11 electric tankless water heaters. Do give a read to that post.

The EcoSmart technology and mechanism used are completely new and it ensures that the user can get endless running hot water. But if you live in a high altitude, we suggest you allow the heater some time to get the thermistor ready. This will make sure that you get uninterrupted hot water from the heater. 

Apart from this, the interior of the product is also very essential and elegant. We found that the interior body is completely manufactured with stainless steel with proper copper components which trigger the efficiency of the heater and allows maximum durability. So it is just a matter of a few seconds to get hot water supply even when you are at a higher altitude. 

The capacity of the EcoSmart ECO 27 is another great advantage to the product. In fact, it can start heating the water even if it is 37 degrees Fahrenheit and automatically heats more than 3 gallons per minute. So even if you have multiple hot water faucets connected to your home, it will never have a problem for you to operate the product at any time.

Specifications

Item Weight: 11 pounds
Product Dimensions: 3.6 x 17 x 17 inches
Flow Rate: 3 GPM
Water Consumption: 35 Gallons
Warranty: 3 Years

Pros

Copper and stainless
Digital temperature control
ECOSMART tankless Technology
Compact design, more storage space
Save up to 50% in water heating costs

Cons

May take time for colder climates
Three 40 Amp Double Pole required
Minimum 200 Amps required

Final Verdict

The EcoSmart ECO 27 has EcoSmart technology which helps in quickly activating the heat and saving up energy as well. So if both safety and cost savings are your concern, it can be an ideal water heater for you to buy. We found it to be extremely professional and working decently in the high altitude areas.

EcoSmart ECO 27 Tankless Water Heater, Electric, 27-kW - Quantity 1, 17 x 17 x 3.5
  • Endless on-Demand Hot Water; Consistent hot water when you need it that never runs out; Continuously monitored water temperature and controlled flow rates ensure efficiency and consistent performance within 1 degree of selected temperature
  • Save Space; EcoSmart tankless electric water heaters are 90% smaller than traditional tank heaters; may be installed on wall or at point of use; Dimensions 17 x 17 x 3.75 inches
  • Save Energy; EcoSmart tankless electric water heaters are 99% thermal energy efficient; Only heats water when called unlike a tank heater that maintains water temperature even when not being used. Save up to 50% in water heating costs according to the Department of Energy
  • EcoSmart ECO 27 Sizing; Refer to the sizing map. Requires 3x40 AMP Double Pole Breaker, 27-kilowatt tankless electric water heater ideal for providing hot water for whole home applications; provides between 2.7 and 6.5 gallons-per-minute depending on the inlet water temperature; refer to the sizing guide to select the proper solution
  • Warranty and Certifications; Limited Lifetime Warranty on electronics, exchanger and element; UL-499 certified; ETL Listed

3. Rheem RTEX-18 Tankless Water Heater

If you are living in high altitudes, you need a product that will have an instant heating feature. Precisely, the heater has features including durable copper immersion which means that you can get two heating elements. So this initiates a fast heating option which makes it more effective for use. Because of this feature, it becomes a matter of a few seconds to get your heater ready.

Coming to the efficiency of the product, the heater seems to be a top-notch choice for those who are looking for 99% energy efficiency. Though the flow rate seems to be a bit average, it is still quite efficient. The flow rate of 4.4 GPM is an astonishing feature in the Rheem RTEX-18. This means that it is a great option for you to run your home faucets for dishwashing, cleaning and even showers.

We also found out that the Rheem RTEX-18 comes with a digital temperature display that provides an accurate reading for the temperature inside the heater. So you can always get a live monitoring option to get proper results. So the safety factor is always taken care of by the manufacturers without any issues at all. 

The Rheem RTEX-18 has an efficient thermostatic control which comes with an LCD. We found the display to be small in size but it is still quite effective when you need to regulate the temperature. So choosing the heater on the presence of this feature can be a great option for you. Moreover, it just took 2-3 minutes for us to install and we could use the product just after 10 minutes. 

Apart from this, we found that the product comes in a compact size and a lightweight body. Moreover, the dimensions are around 4 x 15 x 19 inches which means that it can easily be installed in any corner of your bathroom. We also found that it weighs only 8.5 pounds which means that carrying the product and wall mounting is much easier. 

What we liked the most about the product is the presence of self-modulation power. This is a smart feature for the Rheem RTEX-18 which senses the current temperature of the water and adjusts the heat according to this. Also, the presence of the dual heat coil makes sure that the heater responds much better for higher altitudes.

Specifications

Item Weight: 8.5 Pounds
Product Dimensions: 4 x 15 x 19 inches
Flow Rate: 4.5 GPM
Water Consumption: 20 Gallons
Warranty: 1 Year

Pros

External digital thermostatic control
Durable Copper immersion
Two heating elements
Threaded for easy replacement

Cons

Flow Rate is a little low

Final Verdict

The Rheem RTEX-18 comes with a decent flow rate which means that the product is efficient for regular residential use. Though we find it a difficult choice for big families, you can use the product for small families and personal use. The flow rate and the control features allow you to set the temperature as per your requirement.

Rheem 18kW 240V Tankless Electric Water Heater
  • External digital thermostatic control with LED display (+/1 degree accuracy)
  • Most advanced self-modulation, adjust power to meet hot water demand
  • Durable Copper immersion two heating elements, field Serviceable. Flow Rate- up to 4.4 GPM
  • Simple installation – bottom 3/4 inch NPT water connections
  • Threaded for easy replacement, simple installation, digital temperature display

4. Stiebel Eltron Tempra Plus 36 KW

The Stiebel Eltron Tempra Plus 36 KW seems to be a decent product when it comes to high flow and efficiency. The Stiebel Eltron Tempra Plus 36 KW comes with an on-demand supply for hot water which ensures that you can get instant hot water supply just when you need it. It helps to conserve electricity and energy which can provide more stability to the heater for the longer run. 

When it comes to high performance, the product has a feature to allow silent operation which makes the product a reliable use for hotel rooms and a busy schedule. You can also get electronic switch activation for the silent operation. Even in the hilly areas where the surrounding is silent, you will not have any problems to operate with the product.

Coming to the internal body and the resistance of the heater, we found it to be completed all the safety measures. It includes a copper sheathed heating operation which is a great feature for heating. This is very helpful if you are using a copper cylinder. This makes sure that the product is safe from all sides and will give you a proper response to the durability. 

While installing the product, we found that the Stiebel Eltron Tempra Plus 36 KW is quite decent in weight and weighs around 19 pounds. In fact, the dimensions are also precise and around 16.5 x 4.6 x 14.5 inches which makes it easier for you to install. So if you want to wall mounting options, you need two brackets with the product.

Apart from this, we found that the Stiebel Eltron Tempra Plus 36 KW comes with a decent water flow capacity which is nearly 3.9 Gallons per minute. We feel that this rate of flow is quite decent if you have multiple faucets including 3-4 bathroom and 2-3 showers. The capacity of the product is one of the highest in the segment with 7 Gallons per minute. 

We also found that the Stiebel Eltron Tempra Plus 36 KW has a smart microprocessor technology which makes it much easier for the heater to operate. In fact, the technology is capable of providing the proper control to the temperature. For this, you can get a separate knob that acts more like a temperature switch which includes proper monitoring of temperature. 

Specifications

Item Weight: 19 Pounds
Product Dimensions: 16.5 x 4.6 x 14.5 inches
Flow Rate: 7.0 GPM
Water Consumption: 36 Gallons
Warranty: 5 Years

Pros

Digital temperature control
No venting required
Sleek design fits anywhere

Cons

It does not work with 200 amps

Final Verdict

The Stiebel Eltron Tempra plus 36 KW comes with low power consumption with heat radiant technology that helps to conserve energy as well. Apart from this, it has proper coiling with copper material which ensures that you can get a long life from the heater at the same time. Considering the budget and the performance, it can be a value pick.

Stiebel Eltron Tempra 36 Plus Tempra Plus 36 kW, tankless electric water heater with Self-Modulating Power Technology & Advanced Flow Control
  • Digital temperature control
  • Proven reliability. No venting required.
  • DRAWS 150 A. Requires minimum 300 A electric service. Dimensions (H x W x D): 14.52" x 16.54" x 4.61"
  • Sleek design fits anywhere
  • Save at least 15-20% on the hot water portion of your electric bill.Requires 240 or 208-Volt. Reduce water flow rate until power light on front cover stops blinking

5. Takagi T-KJr2-IN-NG Hot Water Heater Review

The Takagi T-KJr2-IN-NG is a completely gas-powered water heater that not only provides efficiency to the heating requirements, but it is also fast and effective for you to use. The product is quite efficient on the energy factor which is just around 0.81- 0.83. So considering the amount of hot water per unit is quite high.

Coming to the safety concerns, this product comes with a water safety control knob. This knob operates like a temperature control valve which makes sure that you can regulate the temperature when it gets above the recommended temperature. It also has an internal freeze protection system which makes the heater perfect for winter use.

 The Takagi T-KJr2-IN-NG has a high heating capacity and because of the high heating unit, the product takes very little time to heat the water. It comes with a high 140000 BTU which means that you can also get a proper response from energy efficiency. So even if you run the Takagi T-KJr2-IN-NG for long hours, it will be no harm at all. 

If you have a big family, you need a high flow rate from the heater. This product comes with a 6.6 GPM flow rate. This is quite beneficial for you when you are having any occasion in your home and you require a high flow rate for all the faucets. So it ensures that you do not have any issues while using the heater for multiple purposes. 

We found that the product comes in a sleek and simple which means that it is easy to install and also light in weight. Specifically, the weight is just around 37 pounds while the dimensions are around 6.7 x 13.8 x 20.3 inches. This also ensures that the installation takes less time and is more convenient. 

It has an individual inlet and outlet thermistor to help you in constant temperature monitoring. This helps you to regulate the temperature according to the weather and requirements. Though you may not get any digital monitor for recording the temperature, you can get an Auto-Pilot feature. This feature helps you to run the product automatically. 

Specifications

Item Weight: 37 pounds
Product Dimensions: 6.7 x 13.8 x 20.3 inches
Flow Rate: 6.6 GPM
Water Consumption: 40 Gallons
Warranty: 5 Years

Pros

Comes with Durable Body
Includes high-temperature Range
Allows Dual Venting
Energy factor of 0.81-0.83

Cons

It requires venting for installation.

Final Verdict

The Takagi T-KJr2-IN-NG is a top-quality product if you want to get a gas-based water heater for your regular use. It has a decent flow rate which can help you to complete multiple works for your home easily. Considering the budget, it can be a great purchase as your first tankless water heater.

Takagi T-KJr2-IN-NG Indoor Tankless Water Heater, Natural Gas
  • 140,000 BTU. Voltage: AC 120V
  • 6.6 GPM max flow rate. Water connection location- bottom
  • 4-Inch category III stainless steel venting required
  • Inlet, outlet thermistors for constant temperature monitoring
  • Energy factor of 0.81-0.83

6. Noritz NRC661-DV-NG Tankless Water Heater Review

The Noritz NRC661-DV-NG comes with a decent tankless mechanism which is quite fruitful for your regular use. In fact, it uses both electricity and gas for heating the water. The electricity is specifically used only for ignition thus conserving both gas and energy while the heater is performing. So it makes sure that you do not face any problems.

Since it has energy star ratings, we found the Noritz NRC661-DV-NG to be highly effective. In fact, the efficiency rate is just around 93%! Adding to it, the energy consumption is around 15,000 BTU to 120,000 BTU per hour which helps you to conserve the energy at times. 

Coming to the pollution and NOx emission, the heater seems to be very safe in this performance as well. The Noritz NRC661-DV-NG comes with low NOx production that keeps the environment-friendly. The heater works with the updated technology that produces the least amount of NOx to make it environment-friendly.

The Noritz NRC661-DV-NG has dual mounting options so that you can install the heater in both horizontal and vertical positions. We also found the installation to be easy this means that it saves both time and space for the product. 

Coming to the energy ratings of the product, we found that it has a consumption of 138 watts while running in the winters. The overall energy factor is decent and around 0.91. The product comes with low power consumption with high energy ratings. This means that the Noritz NRC661-DV-NG is great for use in the long hours with more options. You can get high efficiency in energy consumption.

What we like the most about the heater is that the Noritz NRC661-DV-NG comes with a high water outflow rate. This means that even if all the hot water faucets are open, you can still get a decent flow all over your home. Eventually, it is around 6.6 gallons per minute which we feel is quite decent for any water heater that you will use regularly.

Specifications

Item Weight: 38 pounds
Product Dimensions: 6.7 x 13.8 x 23.6 inches
Flow Rate: 6.5 GPM
Water Consumption: 35 Gallons
Warranty: 3 Years

Pros

Endless hot water
Very high efficiency
Compact Space Saving Design
Low NOx

Cons

Only 3 temperature settings
Not good for multiple faucets

Final Verdict

The Noritz NRC661-DV-NG seems to have a decent capacity along with a decent water flow rate. Though we feel that it is not such a great choice for multiple faucets in your home, you can still use the device for small families. It can be a good choice considering the budget.

Sale
Noritz NRC66DVNG Indoor Condensing Direct Tankless Hot Water Heater, 6.6 GPM - Natural Gas
  • Endless hot water
  • Can be vented with Schedule 40 PVC Pipe and Fitting
  • High Efficiency
  • Low Nox
  • Remote thermostat & 6' power cord included

7. Takagi T-K4-OS-NG Hot Water Heater Review

The Takagi T-K4-OS-NG is ideally a self-modulating product that is capable of delivering you the best results. We found that the heating unit is quite fast and efficient which is quite decent. The product comes with almost 1,90,000 BTU unit consumption, which we feel is unique, for any water heater for your home. Since it consumes low energy and electricity, you can run the product for long hours.

Coming to the energy efficiency of the product, we found that it is around 0.83 units for this model. Since it can easily heat the water from a range of 99 to 167 degrees Fahrenheit, we feel that this is a decent contribution for any tankless heater. In fact, it also has a dip switching feature which allows you to control the temperature rise. 

The flow rate for the Takagi T-K4-OS-NG seems to be highly impressive and it can easily allow your big family to rush and have a bath. It comes with an 8.0 GPM max flow rate. This means that even if you have several hot water faucets connected in your home, it will not be an issue to use the Takagi T-K4-OS-NG for long hours. The heater can almost support 4 showers running at the same time. 

We found the Takagi T-K4-OS-NG to be extremely light in weight around 38 Pounds. Since it is completely light in weight and there is no venting required, installation may become easier. You can also get the option to wall mount the heater both horizontally and vertically

The one thing that we like about the Takagi T-K4-OS-NG is the safety concerns that it measures with. The product has protective valves for overheating as well as from protecting the interior. The Takagi T-K4-OS-NG has Built-in freeze protection which is another unique feature. This feature helps the user to protect the internal pipe and water from freezing if you are staying in a chilly locality.

Since the product comes with a digital temperature monitoring option, we found it to be very helpful to check the temperature. Also is notifies the presence of a gas flame in the ignition so that it can alert you as always. So even if you are running out of gas, the alarm will start notifying you always. In case, you want to read more reviews for gas-type water heaters then we have got you covered with this article.

Specifications

Item Weight: 38 pounds
Product Dimensions: 8.5 x 13.8 x 20.3 inches
Flow Rate: 8.0 GPM
Water Consumption: 35 Gallons
Warranty: 3 Years

Pros

190000 BTU
8.0 GPM max flow rate
No venting required
Built-in freeze protection

Cons

May start emitting sound while heating the water.

Final Verdict

The Takagi T-K4-OS-NG Water Heater comes in a fairly low budget and getting so many features at this price can be a real advantage for you. So if you want to consider the budget as a factor with proper features, the Takagi T-K4-OS-NG is the right pick for you.

Takagi T-KJr2-OS-NG Outdoor Tankless Water Heater, Natural Gas
  • Outside installation only; Includes internal freeze protection
  • 19,500 - 140,000 BTU/hr
  • 0.82 energy factor
  • 6.6 GPM max flow rate

8. Rheem RTGH-95DVLN Tankless Water Heater

The Rheem RTGH-95DVLN comes with a high condensing body which is specifically made with stainless steel to avoid any type of debris formation or corrosion inside the heater. So even if you stay in a hard water locality, the heater will still provide you with ultimate support. The body is heat condensing from inside which allows the heater to not get affected.

The product comes with a complete digital controller long with remote control for the operations. This operation ensures that you can have a close look at the control flow. Because the product comes with a water-saving feature. Because of the advanced technology, it is capable of saving more than 1100 gallons of water per year.

We found that the heater comes with a decent energy factor rating which is nearly around 0.94. This means that the product is highly energy-efficient and always gives you a proper response to the water flow requirements. Since it consumes low energy, the product is capable of delivering your proper performance even after long hours of daily use. 

The Rheem RTGH-95DVLN has a decent body weight which is around 82 pounds. Since the dimensions are around 27.5 x 9.8 x 28.5 inches, we feel that the best way to use the product would be horizontal. Even because of this, you can easily install and use the product likewise. It just takes two minutes for wall mounting and installation.

It has a unique feature like the freeze protection which makes the Rheem water heater a great pick in terms of high altitude. It has features like Hot Start Programming. This feature is very unique if you are staying in a chilly place and it takes a long time to defrost the water and then heat it. You can even use the heater where temperatures are around – 30 degrees Fahrenheit.

The gas consumption of the heater is also quite decent. It consumes around 199900 BTU which makes the product a decent buy when you have to use the product at the lower temperatures. Because of this heating feature, it becomes easy to trigger the heat and then reduce the time for heating the water inside. You can also read our latest post on reviews of Rheem water heaters to analyze more before buying the water heater of your choice.

Specifications

Item Weight: 82 pounds
Product Dimensions: 27.5 x 9.8 x 28.5 inches
Flow Rate: 8.0 GPM
Water Consumption: 40 Gallons
Warranty: 5 Years

Pros

Freeze Protection
Energy Star Approved
Self-Diagnostic System

Cons

Not Suited for Smaller Families

Final Verdict

The Rheem RTGH-95DVLN comes with a simple and compact body which makes it an efficient buy for your home. It is easy to install and the quick heat function is highly effective. Ideally, we found it to be an ideal choice for people with large families and get the best results.

Rheem RTG-95DVLN-1 Water Heaters, Gray
  • EcoNet is the Brains of Rheem Smart Air and Water Products, using the latest in sensor technology, the EcoNet Smart Monitoring System offers a new level of protection, comfort and energy savings
  • Flow rate range from 0.26 GPM minimum to 9.5 GPM maximum flow rate
  • Temperature varies from 80F minimum to 140F maximum temperature, preset at 120F from the factory
  • Electronic ignition requires 200 watts, and provides reliable ignition for many years
  • Constructed from copper and stainless steel for rugged durability

9. TAKAGI TH3OSLP

The TAKAGI TH3OSLP has a decent structure and capacitor which allows quick heating options for the heater. The TAKAGI TH3OSLP Water Heater comes with an inlet and outlet thermistor which helps in regular monitoring. So you can always keep a check on the current temperature of the water inside.

Coming to the installation options, we found the product to be easy to install because of the lightweight nature and the other features. It comes with wall mounting features which means that it becomes easy to install the TAKAGI TH3OSLP Water Heater. Moreover, the product is light in weight which means that you can transfer it from one place to another.

The body of the TAKAGI TH3OSLP is par at power conservation and energy savings because of the mechanism it follows. The product has radiant heating options which are very helpful to conserve both electricity and gas. Because of this technology, the TAKAGI TH3OSLP Tankless Water Heater can easily support long working hours.

High altitude for the TAKAGI TH3OSLP is not as great as it can take up a long time to heat the water. But if you are staying in an average altitude place, you can turn the thermistor to the full capacity to get the best results. However, in such situations, the power consumption of the product may increase a bit.

Coming to the built and the bodyweight of the product, we found it to be light and a decent purchase. In fact, because of the stainless steel interior and ABS body, the product only weighs around 59 pounds. This makes sure that the product becomes easy to install and use. We found that the product also comes with mounting options which makes it much more convenient to use. 

Another interesting feature of the TAKAGI TH3OSLP is that it comes with a temperature valve regulator. This feature is very helpful to protect your heater from any type of serious damages or any type of overheating damages. So even if you are using the heater for a long time, you will not have to worry about any overheating damages. 

Specifications

Item Weight: 59 pounds
Product Dimensions: 21.8 x 15.6 x 33.2 inches
Flow Rate: 10 GPM
Water Consumption: 40 Gallons
Warranty: 3 Years

Pros

Electronic Ignition
Suitable for Commercial Application
Internal Freeze Protection System
Power Direct Vent Design Provides Flexible

Cons

Heating in High Altitude is Not so Good
May take time to Defrost

Final Verdict

The TAKAGI TH3OSLP is a budget-friendly pick if you want to get for one bathroom. It has the latest technology which quickly heats the water without conserving electricity. It is great for a small family.

TAKAGI TH3OSLP Tankless Water Heater
  • Inlet, outlet thermistors for constant temperature monitoring
  • Perfect for light residential and radiant heating applications
  • Manufactured in Japan

10. Stiebel Eltron Tempra Plus 24 kW Tankless Water Heater Review

If you have a compact bathroom that is space-saving, you need a water heater that will match the thoughts. The Stiebel Eltron Tempra Plus 24 kW is one such product with a sleek and stylish model that saves space and fits perfectly to any wall. Specifically, the dimensions are 21 x 19 x 8.5 inches which makes it look slim and useful. The weight is just around 8 pounds which means that wall mounting is never a problem.

The safety features of the heater are always a top priority for the manufacturers and this is the reason why they have so many safety features. In fact, the Stiebel Eltron Tempra Plus 24 kW comes with a digital temperature control feature that allows you to monitor the temperature in the heater. So you can easily keep an eye on how quickly it is getting warm.

Coming to the performance, we feel that the heater does an amazing job even in the high altitude areas. The Stiebel heater can easily ignite the heat quickly and fire up the water to 131 degrees Fahrenheit. While testing the product, we found that it took 30 seconds to get ready. However, you can expect this time to be around 50 seconds for high altitude areas. 

If you are willing to buy the Stiebel Eltron Tempra Plus 24 kW, we suggest you use in a vertically because you can use the dimensions. Since it is light in weight, you can just add two brackets on the wall and then attack it. When we tried it, it just took 2 minutes to complete the installation.

We also found that the hot water flow rate is quite decent and it is around 5.5 gallons per minute. But, it includes a self-modulating power technology. This helps to keep the heater off while you are not using the hot water and keeps a check on electricity consumption. So even if you use the heater for a single bathroom, it can save you gallons of water all around the year.

The built material of the Stiebel Eltron Tempra Plus 24 kW Water Heater is solid and robust which ensures that the material is quite efficient for long durability. The internal coil is made up of 100% copper and a stainless steel interior makes sure that you can always get corrosion-free material. So you can always get a long life of the product.

Specifications

Item Weight: 8 Pounds
Product Dimensions: 21 x 19 x 8.5 inches
Flow Rate: 5.5 GPM
Water Consumption: 35 Gallons
Warranty: 2 Years

Pros

Digital temperature control
Proven reliability
No venting required
Sleek design fits anywhere

Cons

The power requirement for ignition is high

Final Verdict

The Stiebel Eltron Tempra plus 24 kW comes with advanced flow control which is very helpful to conserve both water and electricity. This flow control ensures that you can get a continuous flow of water and also conserve water throughout the year. So if you are willing to buy a heater for single-use, the Stiebel Eltron Tempra plus 24 kW can be a great buy. 

Benefits of Tankless Water Heaters

The Tankless Water Heaters are the innovation of saving space and time to heat which is now being a common practice to almost every home. There are indeed several benefits to using a Tankless Water Heater for your regular showers. Some of them are listed below:

1. Compact

Most of the tankless water heaters are compact. Since they do not have the storage tank present, they do naturally come in a compact size. This allows you to easily install it in any corner of your bathroom. But the best part is that you can arrange the alignment in both horizontal and vertical position according to the space available in your wall. This takes very little space and ensures that you can get a good fit. 

2. Conserve Water

The other benefit of using Tankless Water Heater is that it allows you to conserve water. They are designed to eliminate the standby losses even for heating and water conservation. The heating element ensures that it is not heating the entire tank so that and even when the water remains unused, the energy gets wasted. So this technology ensures that no water is being waster and only heats the water that is being passed through the output pipe.

3. Save Time

The Tankless Water Heaters are designed to save time. Usually, the tank based heaters come with a light heating element that heats the entire water present in the tank and then allows the water to flow. But, the mechanism is not similar to the Tankless Water Heaters. They are designed in such a way which will only heat the water flowing through the pipe. Thus, it takes just a few seconds for them to get ready. 

4. No Limit

Unlike the tank-based water heaters, the Tankless Water Heaters have a different mechanism for water flow. The tank-based heaters come with direct heating technology and so it does not depend on the water that is stored in the tank. Hence there is no limit of hot water flow from the faucet. In fact, it can keep providing you hot water for long hours even if you have an occasion at your home. 

5. Long Life

Some of the tank-based water heaters; the water remains stored in the tank for long hours. If you have hard water in your locality, there are numerous chances for sediment formation in the tank. This may also lead to corrosion within the tank. But with the Tankless Water Heaters, there is no storage tank present and thus, there are lower chances of sediment formation. Moreover, their long life is roughly around 20 years.

Rinnai RUC98iN Ultra Series Indoor Natural Gas Tankless Water Heater, Twin Pipe
  • INDOOR installation only. Fuel Type: NATURAL GAS.
  • Concentric or PVC venting option
  • Up to 0.96 Energy Factor/Up to 0.92 Uniform Energy Factor
  • The space-saving design allows Indoor Installation type
  • Ultra low NOx emissions

Buying Guide – Factors to Choose the Best Tankless Water Heaters

There are so many tankless water heaters available in the market today. Choosing the best tankless water heater out of them can always be a daunting task in your hand. But if you understand the mechanism and follow the factors, things can get easier for you. For the most effective results, you can follow the Buying Guide present below.

1. Weight

The weight of the Tankless Water Heater is a very important factor if you are willing to choose a new heater for your home. Choosing a lightweight product means that it will always be easier for you to carry or install the product as per your requirements. Usually, a lightweight product around 10 – 12 pounds will be preferable for you to install easily. 

2. Flow Rate

The flow rate of any Tankless Water Heater ensures how fast the water can flow through the pipe. If you have a large number of faucets present in your home which you want to use for multiple works, it is always important for you to choose a Tankless Water Heater which will have a high flow rate. However, if you want to use it for personal purposes, you can opt for a decent flow rate. Try to choose the one which has between 5-8 GPM which will solve all your problems. 

3. Water Consumption

The next important factor is the water consumption of the Tankless Water Heater that you need to consider. Well, technically since there is no storage present in the heater, there is not much water consumption for the heaters which will allow you to get free-flowing water. However, there is still some water consumption of the heater which allows you to et the instant heating. You can opt for a product that consumes around 35-40 gallons of water. 

4. Power Consumption

The power consumption of the water heater is another important factor if you want to save your costs while running it regularly. Most of the Tankless Water Heaters come with a low power consumption mechanism because it does not have to heat the entire water present. Since it works on the heat injection mechanism, it is very beneficial to have this feature. So make sure that your product has good energy saving ratings. 

5. Size

Installation of the Tankless Water Heater is another factor that you must consider while buying a new product. Make sure that you consider the space available on your wall before you opt to buy a new product. But the real benefit of having a Tankless Water Heater is that you can install it both vertically and horizontally. So make sure that you choose the right size before picking the best product.

6. Energy Factor

The energy factor of a Tankless Water Heater depends on the energy consumption of the heater to the amount of water heater. It is obvious that the higher the rating of the energy factor you have, the better performance the heater gives. The Tankless Water Heater will have an energy factor closer to 0.92 which makes the product highly efficient for regular use. 

7. NOx Production

The basic concept of a Tankless Water Heater is to emit the least amount of NOx in the atmosphere to run the product. The NOx is mostly formed in the case of the gas-based water heater when it triggers the ignition. Try to choose a product that has the least NOx production. It will be the lowest if you buy an electric powered Tankless Water Heater.

8. Heat Generation

The heat generation of any Tankless Water Heater how fast the water will heat up within the heater. Usually, try to purchase a heater which can generate around 1,90,000 BTU. This makes sure that the heat generation is much higher and you can get proper results. The more BTU that you get, the better the performance you can expect. 

9. Ignition Type

There are three types of ignition available for most of the Tankless Water Heater. The gas and electric power are the most common types. There is also a hybrid ignition available that uses parts of both gas and electric ignition. However, the electric models have a high long life since they do not emit any NOx but on the other hand, they maybe just a bit costly to maintain. 

10. Cost

If you are willing to buy a Tankless Water Heater for the first time, you can opt to choose a budget-friendly model. But compromising on the features must never be a priority over the budget. Compromising on the basic safety and requirements of your water heater will hand you to a more costly regular experience. So try to choose a budget-friendly product which has all the essential features. 

11. Long Life

Most of the Tankless Water Heaters come with a high long life which ensures that you can get proper results from the heater performance. Try to look for a heater that will have a decent mechanism but the brand gets you a more long life. This means that your heater has spare parts available in the market. The more long life that your water heater has, the more cost-saving it will be. 

12. Time Taken

The time is taken to heat the water and ready for flow determines the performance of the Tankless Water Heater. Usually, the best heater will take around 30 – 40 seconds to heat up and start flowing water. Though the time may increase a little bit more on high altitude performance. So try to choose the one which will be capable to deliver water from 40 – 50 seconds. 

13. Features

Apart from the basic amenities and performance, try to look for some features which will help you to operate the heater. Features like Temperature display and thermistor control valves can be really handy for you to get the best results. So make sure that you have all the basic features present with your Tankless Water Heater.

14. Warranty

Another important factor is the warranty for the product that you can get. The best brands of water heaters will provide you with 5 years of warranty on the heating element and 1 year with the body. This also ensures that the spare parts will be available in the market for long. So make sure that you get a proper warranty with your product to get better service.

Rinnai RUC98iN Ultra Series Indoor Natural Gas Tankless Water Heater, Twin Pipe
  • INDOOR installation only. Fuel Type: NATURAL GAS.
  • Concentric or PVC venting option
  • Up to 0.96 Energy Factor/Up to 0.92 Uniform Energy Factor
  • The space-saving design allows Indoor Installation type
  • Ultra low NOx emissions

Conclusion

Tankless water heaters are becoming the companion for every home to save water and time. If you still do not have one for your home, you can select any from this detailed article on best tankless water heater reviews. The products mentioned here will ensure that you do not face any problem with your shower time or supplying hot water to your home when you have any occasion. You can also have a look at the buying guide to pick the best product according to your requirements.