Are you hunting for the best tankless water heater 2021 which supplies endless hot water with tremendous efficiency, saves lots of storage, and can be installed easily?
I know everybody wants to cut off their energy bills by replacing the tankless water heater with a traditional tank water heater, still, it needs pretty much time for research to find the best one.
To prevent you from this hectic process, We have made a list of top-rated tankless water heaters.
We have shortlisted Each unit according to the features, user reviews, durability, efficiency, flow rate, safety options, user-friendly mechanism, warranty, etc.
Our team of experts has done intense research and multiple experiments to review each unite honestly.
To enjoy endless hot water by saving lots of bucks let’s dive in
Best Tankless Water Heater Reviews 2021
The best tankless water heater is the one that supplies a sufficient flow rate with the desired temperature rise and can be installed easily with impressive efficiency and compact user-friendly design.
Of course, there are lots of other factors like warranty, customer service, parts availability, etc, but these are the most prioritized ones.
Without further wasting time let’s have a look at our list of the best tankless water heater 2021
#1. Rinnai RU199iN Sensei Super – Top Rated Tankless Water Heater
Endless Hot water with 93 to 96% Efficiency:
Ru199iN provides endless hot water throughout the house with impressive efficiency; the unit provides up to 11GPM with an efficiency of 93 to 96%.
Though this unit is powered with natural gas, still you don’t have to worry about bills because its condensation mechanism is amazing.
It can save more energy without losing your comfort, Also, Sensei RU199iN is certified by energy star as well.
We have written reviews on gas tankless water heaters exclusively. Check them out as well.
Cric-Logic Technology with a Digital Display:
It comes with Cric-logic technology which maintains the flow and temperature by sensing your habits and water usage.
You don’t have to set up water temperature and flow again and again.
Also, it comes with a digital display to adjust the water temperature according to the needs, you have multiple options to set up water temperature and flowrate manually.
Sleek Design with Durable Heat Exchanger:
When it comes to the design, Ru199iN comes with a sleek and compact design that can be adjusted anywhere without covering lots of space.
The manufacturer has claimed that this unit has the same size as a small suitcase.
Furthermore, it comes with ultra-durable stainless steel heat exchangers and parts, both heat exchangers are very durable enough to maintain their efficiency for a long time. that is why the manufacturer provides 10 years of heat exchanger warranty and 5 years of parts.
Its noiseless operation will care for your comfort 24/7, you cant feel the noise even from 1 meter away, you don’t have to worry about noise
Wi-Fi ready with various safety options:
You can control the whole unite with your tablet or mobile, a perfect feature for a lazy person like me.
Wi-Fi ready system will provide an app through which you can control the whole system with any device.
Very easy to clean inner parts:
its internal parts are very easy to access you can easily replace or clean them within a few minutes.
Most flexible venting:
Comes with two-inch venting options which is the most flexible venting option available in the market, you can vent your unite flexibly from the roof or wall.
Low emissions of NOx and SOx:
Though this unit works on gas, still it complies with the standard of south air quality management, a perfect package for environment lovers as well
This is the most powerful, efficient, and durable tankless hot water heater available in the market. Rinnai RU199iN can provide endless hot water instantly by utilizing its thermocric360 recirculation technology to save your bucks by sensing your habits.
Moreover, this is an energy star certified unite with 93 to 96% efficiency on both natural gas and propane.
Its Cric-logic technology is very intelligent to sense your habits and utilize gas according to the usage.
Also, its inner mechanism is very simple, you can easily clean or replace its parts.
Our team can’t found a gas unite yet, which can beat this unite in terms of efficiency, durability, and comfort.
#2. EcoSmart ECO 27 Tankless Water Heater
EcoSmart ECO27 Is built to gives you endless hot water supply by saving your money, space, and time.
The manufacturer claims that it can deliver 3 gallons per minute (GPM) even in the coldest climate with 99.8% efficiency.
Moreover, it comes with advanced self-modulating technology to further save your energy bills by sensing your water usage.
Ideal for small houses and Cabins:
ECO 27 is ideal for small houses or cabins; in the coldest places, it can deliver endless hot water for two showers by saving 50% of electrical bills.
However, in warmer places like the southern United States, it can deliver 6 gallons per minute which is sufficient for 3 to 4 showers and 1 to 2 sinks.
Since we are on the topic, check out our electric tankless water heaters as well if you want to save electric bills.
Digital temperature Controller:
It comes with a digital temperature controller with the functionality to increase the one-degree temperature as an increment which allows you to set the temperature more precisely.
You can adjust the temperature between 80-140 F with the help of a knob.
Compact stylish space-saving design:
Unlike old large and heavy water heaters ECO 27 has a lightweight and compact design, you just have to hang at the wall, small size will save your space sufficiently.
Durable stainless steel components:
When it comes to durability and components replacement, ECO 27 comes with stainless steel and copper components which will last longer and can be purchased easily from the local mart.
Life Time warranty:
Ecosmart manufacturer provides you lifetime warranty of heat exchanger and its elements.
Eco smart Eco27 is built to cut off your electrical bills significantly without hurting your comfort.
Its advanced self-modulating system will cut off your electrical bill by 50% without fluctuating the flow rate and temperature.
I believe this is the best unite for small household cabins and saloons. It will provide a sufficient flow rate for 2 showers and a sink simultaneously with an efficiency of 99.8%.
In warmer regions, you will get more GPM for sure.
Furthermore, the manufacturer provides a lifetime warranty; it is strong proof that this model is ultra-durable, that’s why they are providing a lifetime warranty.
#3. Stiebel Eltron Tankless Heater â€“ Tempra 36 Plus
Stieble eltron is the most powerful electric tankless water heater that can supplies 4.5 GPM even at very low groundwater tmepearature.
The manufacturer has claimed that it can supply a constant flow of 4.5 GPM even at 44f/33f, however, it can supply more GPM in warmer regions.
Furthermore, Tempra 36 comes with german advanced flow technology that can monitor the incoming water temperature and flow rate to maintain the top notch comfort.
Advanced flow technology:
its Advanced flow technology is smart enough to sense the temperature of incoming and outgoing water, you will get constant flow with stable temperature.
Whenever your needs for hot water increase advanced water flow technology will increase the heating capacity.
99% Efficiency with an intelligent self-modulation system:
When it comes to efficiency Stieble Eltron manufacturers adopt an intelligent self-modulation technology to minimize the use of energy.
0.99 energy factor (0.99% efficiency) is more than enough to cut off your 50% electricity bills.
Digital display with a Knob:
Tempra 36 Plus comes with a digital display and a knob to set the water temperature according to the needs.
Compact design with the noiseless operation:
The sleek design and compact design of this beauty will allow you to hang it anywhere. No need of larger space and adequate ventilations
Also, it comes with noiseless technology you will never feel the noise.
Durable Copper heating Chamber:
Stiebel Eltron is ultra-durable with a solid copper heating chambers to maintain the constant heating capacity for years.
Tempra 36 plus is designed to get maximum comfort with impressive efficiency and flow rate.
They have utilized advanced flow rate technology to measure the temperature and flow rate of the inlet and outlet to provide fluctuating free comfort.
We have tested this unit; it is more than enough for an average household with 2 showers and a sink even in the coldest region.
If you want to operate more appliances like dishwashers washing machines etc, you can operate by switching off one of the showers.
Moreover, the manufacturer also integrates the advanced self modulations system to maximize the efficiency of this unite. You will surely get 99% efficiency even in real winter.
#4. Rheem RTEX-18 240V Electric Tankless Water Heater
Advanced self Modulation system:
RTEX-18 is the best tankless water heater currently available in the market in terms of efficiency. It has an advanced self-modulation system which enhances the efficiency of this beauty.
RTEX-18 has a brilliant advanced self-modulation system, it increases the power whenever your needs increase and decrease the power when you don’t need lots of hot water.
External thermostat with 1-degree Increment:
it comes with an external thermostat feature with an electronic system to control the temperature manually with 1-degree increments from 80 to 140F.
This unit can supply 4GPM of hot water even in the coldest regions, which is sufficient for a small family.
Rheem tries their best to build its heat exchangers more powerful to raise the temperature even in real winter.
Compact and stylish Design:
Its compact design will save you lots of storage and can be blend with your home dÃ©cor perfectly.
Easy to install and maintain:
RTEX-18 is compatible with 3/4 inch NPT, you don’t need to go market for several joints, etc.
When it comes to disturbance and noise, RTEX-18 has a soundless mechanism you can adjust anywhere without fear of noise and disturbance
Durable dual Copper chambers:
The manufacturer has claimed that RTEX-18 comes with two extra-durable copper chambers, which are powerful enough to supply endless hot water instantly.
Rtex-18 is the perfect package of efficiency, flow rate, and durability. Rheem utilizes the advanced self-modulation system to increase its efficiency to the next level with an amazing flow rate of 4GPM even in the coldest region.
Moreover, it comes with External digital thermostat control to adjust the temperature with a 1-degree increment.
Rheem has claimed that this unit can provide endless hot water even in real winter.
Forget about the fluctuation of flow rate and temperature this unite is solely built to maintain top-notch comfort.
Also, they have utilized advanced designed to make this unite noiseless and more compact; even you can’t observe the noise from 1 meter away.
#5. Bosch Electric Mini-Tank Water Heater Tronic 3000 T 7-Gallon
98% efficiency with ultra heating capacity:
This is the most compact water heater with an efficiency of 98%, the manufacturer claims that the 3000T7 will supply 7GPM with a heating capacity of 1440 watts.
NOTE: 7 GPM is more than enough for a 2 bedroom household; however you have options to select 2.5 GPM and 4.5GPM as well.
Rise temperature from 65F to 145F:
It can heat water from 65F to 145F which is enough to use even in the coldest regions.
Temperature and pressure relief valve:
modern temperature and pressure relief valve is added to ensure top-notch safety
Compact size with stylish design:
The compact and sleek design will allow you to mount anywhere even you can mount it under the sink.
Also, it can be blend seamlessly with interior decor because of its beautiful design.
Easy Installation no need for large ventilations:
The installation procedure of 3000T is very simple you don’t need to hire a plumber for this. Just read the manual and follow the steps.
Moreover, this unit can be installed both vertically or horizontally without the need of adequate ventilation
Tronic 3000 T 7 is the most compact water heater with a large flow rate of 7GPM.
We are unable to find that much compact unit with 7GPM.
Furthermore, the manufacturer claims that you can install it both horizontally or vertically even you can mount it under the sink as well.
You can hide this tiny unite anywhere, and start using endless hot water by saving lots of bucks.
Another major advantage of this unite is, you can easily shift this unite anywhere because of its easy installation process.
You don’t need to waste more bucks by hiring a plumber its installation is completely DIY.
#6. Rinkmo Electric Tankless Water Heater 18KW 240V
Instant Endless hot water within 3 seconds:
Rinkmo tankless electric water heater is powerful enough to provide you hot water within 3 seconds.
You don’t need to wait for hours, it will supply instant hot water whenever you need it.
Forget about preheating, just you have to tap the knob and enjoy the endless hot water within 3 seconds with the desired temperature.
99.8% Efficiency with a self-modulation system:
It has an impressive efficiency of 99.8% with the smart self-modulation system to cut off your energy bill by 50%.
Rinkmo manufacturer engineered an advanced self-modulation system that is intelligent enough to observe the needs of users.
Whenever the usage increases the heater provides maximum power otherwise it will save electricity.
Stable Temperature of water:
smart modulating system and flow sensors designed with an advanced formula to stale the desired outlet temperature.
Digital display with a flexible Knob:
Rinkmo comes with a stylish digital meter and a knob to adjust the water temperature.
You can adjust the temperature in both Celsius and Fahrenheit by rotating the knob (antilock wise or clockwise),
Compact Space Saving Design:
the clean, compact, and sleek design can be adjusted anywhere, without losing the look of your interior dÃ©cor.
10-fold security technology and auto protection system:
Rinkmo manufacturers utilize 10-fold Security Technology and auto protection systems to make this tankless hot water heater safer.
They have made separate passages for water and electricity to provide extreme protection.
Moreover, when the temperature reaches 167F the unit will shut down the heating system to maintain your comfort and safety.
No expensive maintenance:
Rinkmo comes with an advanced flame mechanism to provide heat without the contact of minerals to stay away from mineral deposits, No need of replacing the heating coil rapidly.
Rinkmo Electric Tankless Water Heater is a buck-saving machine, even though this unite is powered with electrical power, still, it has the capacity to provide 99.8% efficiency just 0.02% losses which is not a big deal.
the manufacturer perfectly utilizes its experience and expertise to make this unit a more reliable, durable, safer, and cost-saving machine.
It will save you 50% cost of energy and maintenance.
Rinkmo electric is the best instant water heater that comes with a very powerful heat exchanger, which can heat water within 3 seconds you don’t need to wait for preheating.
Moreover, its safety features are amazing you don’t need to worry about electrical accidents.
#7. Rheem 240V Heating Chamber RTEX-13
Supply 1.5 GPM with the Efficiency of 99.8%:
RTEX-13 is the latest tankless water heater by Rheem, proved to be more reliable and the user’s friendly as compared to previous models.
It supplies 1.5 GPM with 99.8% efficiency; however the number of GPM increases in warmer places.
Compact design with easy installation:
Compact design will allow you to save more storage and can be installed anywhere without having some mechanical skills
Since its installation is very simple there is no need to hire a mechanic.
No Need for ventilation:
RTEX -13 is equipped with a low NOx emissions system, no need for large ventilation you can install it indoors as well.
Digital display with LCD:
In terms of usage, RTEX-13 is very easy to operate it has a digital meter, LCD, and a knob to adjust the temperature and flow rate of the outlet water.
Easy to maintain:
Easy maintenance will save your lots of time and bucks because you don’t need to hire a plumber to maintain it.
Durable Heat exchanger and pipes:
RTEX -13 has ultra-durable copper heat exchangers and pipes which last for years without reducing the efficiency.
Rheem is the name of reliability they build this unit for a single bedroom, cabin, and saloons with impressive efficiency, space-saving compact, and stylish design with ultra-durability.
Its durable copper heat exchanger is efficient to save lots of bucks without compromising the flow rate and temperature rise.
According to our experience, it can supply hot water to 1 shower and a sink at the same time even in the coldest region.
However, it can significantly increase the flow rate in warmer regions.
#8. ECOTOUCH 90 9KW 240V
ECO TOUCH ECO90 is famous to provide instant endless hot water with a tremendous thermal efficiency of 99.8%.
Forget about preheating you can get hot water within seconds.
The manufacturer has claimed that ECO90B will heat up to 1.5GPM from 67f to 104f with minimum energy cost.
Advanced Smart self Modulation System:
Its smart self-modulation system will supply the electrical power on the demand.
Whenever the supply of outlet water increase the electrical supply somehow increases to maintain optimum comfort.
Digital display to adjust the flow rate and temperature:
ECO90 comes with a digital display to adjust the temperature and Flow more precisely.
Compact design with Easy installation:
When it comes to design and installation, ECO90B has a compact and stylish design that can be installed easily. Even you can install in the kitchen because of the stylish design.
Patent heating technology:
patent heating technology will reduce the chances of corrosion by reducing the mineral deposits in the heating chamber.
Ultra-safe and Durable:
In terms of safety and durability, ECO90 passes through several tests to ensure safety and durability.
According to the manufacturer they have utilized separate leakage-free passages for water and electricity.
The high-grade copper mechanisms of ECO90 can last for years without losing efficiency.
ECO90 is the most stylish water heater I have ever seen in my life. It comes with a very attractive digital display, which allows you to increase our decrease flow rate and temperature.
And the good news is;
This unit passes through several safety tests, you don’t need to worry about electrical incidents.
Furthermore, it comes with an impressive flow rate of 1.5 GPM with 99.8%efficiency, which will significantly cut off your electrical bills.
According to our research 1.5 GPM is sufficient for a couple or a single student, also you can expect more in warmer seasons.
Another major benefit of this unit is, they have added several safety features by separating the electrical and watering line properly.
#9. Hike Crew Portable Propane Water Heater & Shower Pump Review
Works both indoor and Outdoor:
Hike Crew is a powerful portable tankless hot water heater with multifunction to use both indoor and outdoor.
Forget about cold water at the camping, this beauty will provide you continuous hot water at camping.
Supplies 2.2 L/M By consuming 5.7 kWh:
The manufacturer has claimed that it will provide 2.2 L/M on average with the consumption of 5.7 kWh or 15.4oz/h.
The hike crew just needs the supply of propane gas and an AC/DC supply or a simple 12V adopter to heat the water during camping and hiking.
Multifunctional digital meters with step-less knob:
The Digital meter, step-less knob, and gas regulator comes with various adjustments to adjust several things like temperature, gas consumption, and water flow, etc.
- Its step-less knob located at the top will allow you to adjust the temperature.
- A gas regulator located at the propane cylinder will allow you to maintain the gas supply.
- A flow switch to adjust the water flow.
Also, it will allow you to ON/OFF the system or monitor the temperature.
Built-in Shower with 3 sprays:
Also, this tankless water heater comes with a built-in shower with 3 water spray patterns, you can use directly without connecting the tank.
Automatic shut OFF:
When it comes to safety, the hike crew comes with Automatic shut OFF technology.
Whenever the temperature rises from 125F the system automatically shuts OFF.
Compact design with a carrier bag:
hike crew has a compact travel-friendly design with a proper bag to carry all the things safely.
Hike Crew Portable Propane Water Heater is a perfect package for camping, RV’s, etc.
Furthermore, you can utilize it indoors as well, this unite is perfectly designed to use both indoor and outdoor.
Hike crew manufacturer comes with a unique idea to make a portable tankless water heater with lots of modern features like safety features, built-in shower, gas control, flow control, temperature control, etc.
As we have mentioned that this unite is solely built for camping purposes you will get an ultra-compact design with several functionalities to fulfill your camping journey.
The manufacturer tries to make it lightweight with a built-in shower and other kinds of stuff.
#10. Rinnai V65eN Tankless Hot Water Heater
Supplies 6.5 GPM with 82% efficiency:
Rinnai V65eN is the combination of optimum comfort with high thermal efficiency, ideal for medium homes.
V65eN supplies endless hot water with an efficiency of 82%, its durable copper mechanism will last for years without losing efficiency.
Even at natural gas, you will get optimum thermal efficiency with the supply of 6.5 GPM.
Rise temperature from 90F to 140F with preset option:
Temperature ranges from 90F to 140F max, but you can adjust the preset temperature according to your needs.
sufficient temperature ranges can supply endless hot water even in the coldest regions, however preset functionality will maintain your comfort.
Wi-Fi ready with (Control R-2.0 Mobile app):
Control R-2.0 Mobile app will allow you to control the whole unit with your tablet or mobile phone, you can adjust the flow rate temperature etc.
Modern safety features:
Enhanced scale detection system to prevent long-term damage, meanwhile it will monitor the unite to prevent serious damage.
Furthermore, its temperature lock feature will lock the temperature to prevent accidents.
Compact easy to install design:
Sleek and compact design will adjust everywhere by saving lots of space and can be installed easily without hiring a plumber. Even you can install it outdoor as well.
Low NOx and SOx emissions:
It’s NOx and SOx free operation complies with south air quality management.
Long term warranty:
It comes with 10 years of heat exchanger warranty, 5 years of parts, and 1 year of labor.
Rinnai makes a perfect combination of high efficiency, flow rate, and durability.
Though this unit is powered with gas, still Rinnai tries to make this unite extra efficient, you will get 82% efficiency on both propane and natural gas.
Furthermore, its stylish and compact design will save you lots of space and can be blend with your interior dÃ©cor perfectly.
its modern safety features like temperature locks and Enhanced scale detection will care for you and your tankless water heater for 24/7 Hours.
#11. Stiebel Eltron Tempra 24 Plus
Advanced Flow Control technology:
Tempra 24 plus comes with the most Advanced Flow Control which maintains a constant temperature of output water by sensing the ground water.
The manufacturer utilizes smart technology that works automatically to adjust the flow of outlet water to eliminate fluctuation.
Supplies 5.0GPM with 99% efficiency:
Moreover, it will supply 0.59 to 5.0 GPM with an advanced self-modulation system to maintain the temperature and flow rate accordingly to get a 99% efficiency.
However, the flow rate of water may vary in warmer regions.
A digital meter to control the whole unite:
A digital meter is installed to adjust the temperature ranges from 86 to 140F.
Its digital meter is straightforward and users friendly you have options to put your system at self modulations system or you can simply adjust the flow rate and temperature manually.
Compact stylish design:
Furthermore, its sleek and compact design will allow you to mount anywhere without losing the look of your interior.
Its stylish design will blend very well with your interior decor and can save lots of space as well.
Simple installation no need for ventilation:
Its installation and the operating procedure is very simple you don’t need a plumber to install this system, simply you can install it with the help manual.
Another major benefit of this tankless water heater is, you don’t need any ventilation to install it.
When it comes to durability, it comes with an extremely durable copper heating system to maintain efficiency for years.
You will get 7 years of leakage warranty and 3 years of parts warranty, at least you are fearless for the first 3 years.
Its inner mechanism is designed to work silently; even you can hear the noise from 1 meter away.
Stiebel Eltron Tempra 24 Plus is famous for its advanced flow rate technology which has amazing sensing technology to sense the temperature and flow rate of both inlet and outlet water.
Forget about the fluctuations keep enjoying endless hot water with a balanced flow rate and temperature.
Also, its self-modulation system will cut off your energy bills significantly with an amazing flow rate ranges from 0.59 to 5 GPM depending on the region.
Tempra 24 Plus comes with an ultra-durable copper chamber and can be installed easily without the need for ventilation.
Furthermore; you have a digital meter to control the whole unit with the unit.
#12. Eemax EEM24018 Electric Tankless Water Heater
Instant endless with maximum efficiency:
Eemax EEM24018 tankless water heater is designed to get instant endless hot water with maximum efficiency.
This beauty will supply 3.5GPM even in the coldest region which is sufficient for 1 shower and 2 tanks. however, in warmer regions, you will get more GPM.
Advanced self-modulation system:
Advanced self-modulation will maintain the temperature and flow rate according to the needs.
The self-modulation system is very intelligent and energy-saving, whenever your needs increase you will get maximum GPM, otherwise it provides a sufficient flow rate to save energy.
Digital meter with a knob:
A digital meter with a knob is added to adjust the temperature between 80 to 140f with a 1 F increment.
Moreover, you have options to set temperature manually or a self-modulation system will handle it for you.
Compact, easy to install design:
When it comes to design and installations, its compact and stylish design will adjust anywhere without covering lots of space.
Moreover, its easy installation process will save you lots of costs.
Durable Copper alloy heating chamber:
Also, its heating chambers are made from copper, you can expect amazing durability with long-lasting efficiency.
Its advanced self-modulation system is intelligent enough to sense your usage and flow endless water hot water according to the requirements.
This unite can save lots of bucks without disturbing your comfort.
Furthermore, Eemax EEM24018 can supply 3.5 GPM even in the coldest regions, one of our teammate is using this unite from the past 4 to 5 months and he is very impressed with its energy-saving technology and flow rate.
Also, it will significantly increase the flow rate in warmer conditions, so don’t worry about the flow rate.
Its durable heat exchanger is built from the alloy of copper and stainless steel to conduct more heat as compared to the ordinary copper.
Definitive Buying Guide To Select The Best Tankless Water Heater
I know you are going to change your traditional water heater with the best tankless water heater, still, you have to confirm the following things to get the best one.
Determining the required Flow rate (GPM) is very important. Flow rate is represented by GPM (Gallons per minute), the number of gallons you have required for usage per minute.
Let’s make it simple, all tankless water heaters come with a maximum GPM limit, you have to figure out your maximum required GPM to select a feasible one for you.
A normal kitchen faucet will require 0.5 GPM, however, a showerhead will require 2.5GPM.
We have made a list of different appliances with required GPM’s let’s have a look.
|Kitchen faucet (0.5GPM)|
|Lawn system (3-10GPM)|
|Bedroom shower (2.5-7GPM)|
|Clothes washer (1.5GPM)|
NOTE: This is a rough estimation, your faucet, showerhead or dishwasher may release more GPM so please check out manually if possible.
How to determine GPM manually:
To measure the GPM of any showerhead, faucet, etc. you have to follow the following steps.
For E.g: a stopwatch shows 30 seconds now we have to divide 60 by 30 to get a Gallon per minute
60/30 = 2, we successfully found that our showerhead /faucet releases 2 GPM.
CHOOSE ACCORDING TO THE REGION (Right temperature rising capability is very important):
Determination of the groundwater temperature will help you to select a feasible tankless water heater for you.
In warmer regions groundwater may vary from 70 to 90 F, however, in cold regions, groundwater temperature may vary from 30 to 40 F even lower than 30F.
Determining the groundwater temperature is highly important because if the groundwater temperature is extremely cold in your region, and you have purchased a tankless water heater that does not have the capabilities to raise temperature according to the needs.
Probably you have lost your money, isn’t it?
The lower the groundwater temperature higher the time of heating water and the lower the GPM in some cases.
If you don’t have sources to determine the groundwater temperature, let’s do some assumptions or we have got the groundwater temperature map of the US.
How to calculate your temperature Rise:
First, you have to determine the temperature of your groundwater with the help of a thermometer after that your task is to subtract it from your desired output water temperature.
For e.g: your groundwater temperature is about 60F and you need output water at 120F, Then you need to purchase a water heater that has the capabilities to raise 60F.
NOTE: When you set up the water temperature in a tankless water heater it will not decrease or increase automatically, however, the temperature of groundwater may vary so keep changing the temperature according to the needs
And the good news is;
Our list of best tankless water heaters contains some water heaters with an advanced self modulations system which adjusts the temperature automatically.
Few Examples to select the best size with sufficient temperature rising capacity
Example #1. Consider a one-bedroom house in a warm climate with 1 shower (2.5 GPM), 1 faucet (0.5GPM), and a washing machine (1.5GPM).
Now according to calculations, we need a tankless water heater with a maximum flow of 5GPM (2.5+0.5+1.5).
Now let’s assume the groundwater temperature is about 70 F, now we have to select one which can raise 40F or more to get maximum comfort.
In conclusion, we have to select the one which has the maximum flow of 5 GPM with the capability to raise temperature up to 40 or 50 F.
Example #2. Consider the above house in the average climate, now the GPM requirements are the same but we have to figure out the temperature of groundwater.
Let’s assume groundwater temperature is 45 F now we have to select a tankless water heater that can rise 55 F to get maintain our comforts.
In conclusion, we have to select the one which has a maximum flow of 5 GPM with the capability to raise the temperature up to 55 F.
Example #3. Again consider the above house in the cold climate, Now the GPM requirements are the same but we have to figure out the temperature of groundwater again.
Let’s consider groundwater temperature is 30 F now we have to select a unit that can rise 70 F.
In conclusion, we have to select the one which has a maximum flow of 5 GPM with the capability to raise temperature up to 70 F.
Wait we Have to Clarify a few things:
1. You can further calculate according to the needs, we just want to clarify your concepts. Now you can do calculations and select the best tankless hot water heater for you.
2. Most of the unit provide significantly low GPM when groundwater temperature falls, it’s completely fine. If you have selected a unit with sufficient temperature rising capacity you will get close to the mentioned flow rate.
checkout an illustration to get more ideas:
Tankless water heaters are generally powered with gas or electricity, if you have both options available then you have to figure out which is more feasible for you.
According to our research, tankless gas water heaters are more expensive and required annual maintenance with adequate ventilation.
Moreover, they are complex to install you may need to hire a plumber for installation and annual maintenance.
Still, tankless gas water heaters will save more energy in long run, supply more GPM with impressive durability.
Though you have to pay more initial cost, but you will save lots of bucks in the future because gas is cheap as compared to electricity.
On the other hand, tankless electric water heaters are less costly and they don’t require annual maintenance.
Also, tankless electric water heaters are more efficient and environmentally friendly, still tankless electric water heater will supply a little less GPM as compared to Gas Unite, if you are hunting for more GPM gas unite is perfect for you.
If there is the availability of both gas and electricity in your area, then you have to figure out your required flow rate.
If you required more flow rate go for gas unite, otherwise you can go for electric unite.
Moreover, you have the option to purchase more tankless electric water heater units, if you are not interested in gas units.
Tankless gas water heaters are costly and they may require a professional plumber and adequate ventilation.
However tankless electric water heaters are cheaper, comes with a simple installation and maintenance process, you may save the cost of a plumber.
gas tankless water heaters are more energy-saving if you are planning for the long term, as gas is cheaper than electricity.
If you are successful to manage the initial cost you will save your cost of gas in long run.
Though tankless electric water heaters comes with an advanced self-modulation system to increase energy factor up to 99.8%, still electricity is costly for long-term usage.
DESIGN AND SIZE:
Always choose a compact tankless water heater with a stylish design, which can be adjusted anywhere without disturbing the look of your interior dÃ©cor.
Though this is not an important factor, still some peoples want a stylish design and compact size to save more storage.
Keep in mind if you want a high flow rate water heater you may not get an extremely compact size because they have a large mechanism to supply more flow rate.
Choose a tankless water heater that is easy to operate because you have to operate it regularly. If your water heater is very complex you may get frustrate after a certain time.
Lots of manufacturer tries to make their water heater more users friendly even they try to make automatic water heaters to ensure top-notch comfort and safety.
Better to go for a water heater that has a simple installation and maintenance mechanism as well, it will save your mechanical and maintenance cost.
Durability is the most important factor to select the best tankless hot water heater. Everybody is conscious about the lifespan of the tankless water heater, isn’t it?
Ok, let me clarify that lots of tankless water heater comes with copper heat exchangers that can last about 10 to 20 years depending on the quality of copper.
Some expensive tankless water heater comes with a commercial copper alloy which can last even longer than 15 years without losing the efficiency.
And the good news is:
We have tested each tankless water heater on our list; you just have to select one of them.
WARRANTY AND CUSTOMER SERVICE:
Warranty varies from company to company and model to model, some of the manufacturers provide warranty only if your water heater is installed professionally.
Otherwise, your tankless water is not eligible for warranty coverage.
Keep in mind; we have to select a tankless water heater with a long warranty because the manufacturer is dam sure about its durability, that is why they have provided that much warranty.
A lot of companies provide warranty ranges form.
- 10-20 years for heat exchanger.
- 2-5 years for other parts.
- 1-year labor
Moreover, choosing a manufacturer that has amazing customer service will help you to fix any problem instantly.
The price of tankless water heaters ranges according to the quality, flow rate, rise in temperature, fuel, and other features as well.
Some manufactures have utilized premium material to make their water heaters more durable with lots of modern features.
Moreover, they have provided a long-term warranty with impressive customer service as well, they have the right to take a few more bucks than others.
If you need a tankless water heater with more flowrate (GPM) with impressive built quality and modern features, you have to pay a decent amount.
However, if you need a tankless water heater with a low Flowrate(GPM) with average built quality and features you have to pay an average amount.
It depends on you, whether you need more GPM for the whole household or you need sufficient GPM for a single bedroom.
How A Tankless Water Heater Works
A tankless water heater comes without a tank to store the water, you will get instant hot water rather than waiting for hours to get hot water.
Simply it has a strong heat exchanger to exchange heat with water instantly.
Let’s have a look at the whole process.
You can get further information about the mechanism of tankless water heater from here
High efficiency: tankless water heaters are more efferent as compared to ordinary water heaters.
Ordinary water heater keeps supplying heat to the stored water until you turn it off.
However, a tankless water heater senses the water temperature and shut off the system automatically to save energy.
furthermore, lots of tankless water heater comes with an advanced self-modulation system to maintain the efficiency of about 99.8%, just 0.2 energy losses which is not a big deal.
And the good news is;
Our list of the best tankless water heater contains most of the water heaters with the advanced self-modulation system.
Instant hot water: tankless water heater will provide you instant hot water you don’t need to wait, just start the water heater and get the water within 1 minute or even less.
However, the tank water heater will kill your time to heat stored water.
Stylish and Compact design: most tankless water heater comes with a compact stylish design to save lots of storage and can be blended with interior decor.
However the ordinary tank water heater has a large size and old look, you need to hunt a proper space to install them.
Safer operation: lots of tankless water heaters comes with a computerized safety system that senses the temperature of the water and cuts off the heating supply whenever the temperature reaches an alarming level.
User-Friendly operation and installation: tankless water heaters are very easy to operate and install.
Even some tankless water heaters can be installed without the help of a plumber, you just need to read out the instructions.
Tank water heaters are more complex to install and operate you may need to hire a plumber to install that kind of water heater.
Environmental friendly: tankless water heater utilizes a very low amount of fuel to heat the water as compared to a tank water heater, lower the combustion of fuel lower the carbon footprint.
If you are an environmental lover please go for a tankless water heater.
Limited Flowrate: Though there are lots of tankless water heaters that come with more than a 10GPM flow rate, still, this is fixed you can’t get more in cold regions.
However, the flow rate may increase in warmer regions.
If you need more you have to upgrade your existing tankless water heater or you need to purchase another unite.
Several new types of equipment may require initially: different water heaters comes with different installation mechanism.
Some tankless water heaters are capable with 1/4â€ NPT while others are compatible with 1/2â€ similarly you may need some up-gradation in the electrical system as well.
Well, switching from a traditional water heater to the best tankless water heater is a good decision for those who want instant hot water by saving energy bills and storage.
Furthermore, a tankless water heater comes with a simple installation, maintenance, and operation process with lots of safety features.
Some unite comes with Wi-Fi ready system you can control them with your tablet as well.
As we have discussed in the buying guide that you have to check out your flow rate temperature rise, size, and most importantly whether you want an electric or gas unit.
You just have to calculate your needs and select one from our list.
Here are our recommendations:
Rinnai RU199iN Sensei Super High Efficiency is the best tankless water heater for those who want to purchase a gas unite for the whole household.
Ecosmart 27 is the best electrical unit for an rage household
Rinkmo Electric Tankless Water Heater is best for a small household.
Frequently Asked Questions – (FAQs)
Q: Is it possible to replace a tanked water heater with a tankless water heater?
Yes, you can easily replace a tankless water heater with your old water heater.
Q: Can I install a tankless water heater?
It depends, some water heaters are complex to install without having prior experience.However, there is lots of tankless water heater comes with detailed manuals and simple mechanisms to install it.
Q: Do you run out of hot water with a tankless water heater?
Not at all, if your calculation is right, if you have a unit with a 2GPM flow rate and you want to use the only shower you will never face hot water shortage. If you are going to use other things like sinks, washing machines, etc at the same time you may face a deficiency of hot water.
The manufacturer mentions the flow rate we have to calculate before purchasing.
Q: Can a tankless water heater fill a tub?
Yes why not, as we have mentioned early tankless water heater supply continuous hot water in GPM (gallon per minutes) you can fill out the 10 gallons tub within 10 minutes if you have 1GPM unite.
Q: Can a tankless water heater be vented through the roof?
Yes, of course, you can install some models outdoor as well but keep in mind read out the instructions carefully, if they allow outdoor then you are good to go.
Q: Can a tankless water heater be installed inside?
Yes, most of the tankless water heaters are installed inside, however, gas units mostly required adequate ventilation while electric doesn’t need ventilations at all.
Q: What is the downside of a tankless water heater?
Fixed or limited flow rate is the major downside of a tankless water heater; we can’t expect a 6 GPM flow rate from a 4GPM unite.
Q: What size of tankless water heater do I need?
Depending on the flow rate you need, normally 7 GPM is enough for an average household with 2 showers a sink, and a dishwasher. We have mentioned the flow rate and temperature calculations in the Buyer guide let’s have a look, your all doubt will be clear.
Q: What happens if you don’t flush your tankless water heater?
If you will not maintain (flush) the water heater, mineral deposits may be sustained in the tank and produce clog in the unit. Which may reduce the efficiency and heating capacity of your unite; you may face temperature fluctuation etc.
Q: Can you sleep in a room with a tankless water heater?
Please don’t do that, though most companies claim that their water heater is very safe with computerized safety features, still it is a type of machine which can be failed anytime. Don’t take risks always keep your water heater away from your bedroom.
Q: How much does it cost to descale a tankless water heater?
Honestly, we can’t calculate the exact amount because rates vary from company to company. We can give you rough estimations, $100 to $200 will be the total cost of tankless water heater service. They will diagnose each part to ensure the unite works properly; this should include the descaling, filter service, replacing, etc.
Q: Do tankless water heaters need maintenance?
Yes, some tankless water heater needs maintenance like extract different deposits to prevent from rusting, etc. However, there are lots of units we have listed above that do not require any maintenance at all.
Q: What is the lifespan of a tankless water heater?
The most tankless water heater has a lifespan of 15 to 20 years; also their parts can be replaced easily.
Q: What size of tankless water heater do I need?
Again it depends on your requirements, tankless water heater available with different flow rate ranges from 3 to 10 GPM. According to our experience, 4 GPM is enough for couples, however, 8 to 9 GPM is sufficient for 5 family members.
Q: How often do you need to clean a tankless water heater?
A tankless water heater should be flushed at least 1 time in a year to maintain efficiency. However, it is better to flush your water heater 2 to 3 times a year to prolong the lifespan of your water heater.
Q: Can I use CLR to clean my tankless water heater?
Yes, cleaning a tankless water heater with CLR is easier than ordinary water, make a solution of CLR and start cleaning your water heater.