Best Tankless Water Heaters in 2020: Reviews and Rating

107 Products Evaluated
97 Hours of Research
4 Experts Interviewed
721 Reviews Analyzed

Last updated: 22.05.2020 by Rex Cauldwell

Ok, at this point, you’ve probably heard about the advantages of tankless water heaters.

You get endless hot water with slashed energy costs from a system that takes up less space and lasts much longer than traditional conventional storage tank water heaters. It’s more environment-friendly and you’re never wasting energy by heating and reheating the same water over and over again.

Whether you’ve got a 3-bath home or a small RV, the question becomes, how do you go about getting the best tankless water heater for your needs?

It’s your lucky day! We’ve done the hard part of comparing the models’ specs and prices, reading countless online reviews from (verified) owners, and surveying numerous real-life homeowners, contractors, plumbing, and electrician professionals to find out what are the best tankless water heaters for every possible situation. 

The result is this website. Simply choose the right article and follow the recommendations.

And if you’re not sure where to start from, look through our list below or choose one of the three fuel types here and dive into the detailed reviews. 

Tankless Water Heaters Comparison Chart

Here, we’ve covered the best commercial and the best residential tankless water heaters on the market, including natural gas, propane, and electric models. Most of these water heaters are best suitable for mid-size homes or high-demand households in warmer climates. For high-demand houses in the north, we reviewed special gas tankless water heater models with high GPM and BTUs. We also included electric tankless water heaters for small houses, apartments, condos, and low-demand households in general.

If you’re not sure what size tankless water heater is right for you, please refer to our detailed sizing guide.

If not specified otherwise, the warranties are honored by all of the manufacturers even if you buy through Amazon since it’s an authorized retailer.

Tankless Water HeaterAdvantagesGPMApproximate UsageRating & Price
Rinnai RUR199iN Sensei Natural Gas Tankless Water Heater
Rinnai RUR199iN Photo
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  • UEF (Efficiency Rating): 0.93
  • BUILT-IN recirculation pump with a timer works even without a dedicated return line
  • Energy Star® certified
  • It sustains high GPM flow rate for low temp income water
  • Highest GPM (with prarmeter adjustment)
  • Multiple venting options
  • Wi-Fi ready (with additional module)
11*5/5
⭐⭐⭐⭐⭐
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Rinnai V65iN Natural Gas Tankless Water Heater
Rinnai V65iN Photo
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  • UEF (Efficiency Rating): 0.8
  • Energy Star® certified
  • Several sizing options
  • Can easily replace 50 gallon tank
  • Accurate temperature control
  • Durable heat exchanger
  • Timers and schedules for heating water remotely with an app
9.8*4.5/5
⭐⭐⭐⭐⭐ CHECK PRICE
Stiebel Eltron Tempra Plus 36 kW Electric Tankless Water Heater
Stiebel Eltron Tempra 36 Photo
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  • German quality
  • Great customer service
  • Innovative features (like Advanced Flow Control and more)
  • Very quiet
  • Easy to intall and use
  • Saves you money over time
7.5*5/5
⭐⭐⭐⭐⭐ CHECK PRICE
Ecosmart ECO 18 Electric Tankless Water Heater
Ecosmart ECO 18 Photo
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  • Affordable and efficient (99.8% energy efficiency)
  • Lifetime warranty for residential use
  • Compact and durable
  • Digital temperature control
4.5*5/5
⭐⭐⭐⭐⭐ CHECK PRICE
Rheem RTEX-13 Professional Tankless Water Heater
Rheem RTEX-13 Photo
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  • 99.8% Energy efficient
  • Very compact sizes
  • Simple installation
  • Perfect choice for cottages, cabins, condos, small houses, single bathroom houses or apartments in warm climates
  • Saves you costs on electricity due to high efficiency
3*4.5/5
⭐⭐⭐⭐⭐ CHECK PRICE
Bosch Tronic 3000 (mini-tank)
Bosch Tronic 3000 Photo
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  • Perfect for apartments, RVs and Boats
  • It's very compact in sizes and can fit under sink
  • It's cheap
  • Fits easily under a sink
  • Instant hot water
1.5*5/5
⭐⭐⭐⭐⭐

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Takagi T-H3-DV-N Tankless Water Heater
Takagi Photo
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  • UEF (Efficiency Rating): 0.93
  • Relatively low price
  • You can easily increase default maximum temp in the settings
  • Energy Star® certified
10*4/5
⭐⭐⭐⭐ CHECK PRICE
Rheem RTGH-95DVLN Tankless Water Heater
Rheem RTGH-95DVLN Photo
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  • UEF (Efficiency Rating): up to 0.93
  • Easy installation and service with self-diagnostic system
  • Digital remote control included
  • Freeze protection to -30°F
9.5*4/5
⭐⭐⭐⭐ CHECK PRICE

*This is the maximum possible flow rate for warmer climates. For real flow rate check the individual reviews. We’ve put a table of max. GPM for different temperature rises.

Best Tankless Water Heater Reviews

Here goes a list of the best tankless water heaters on the market right now:

1. 🥇 Rinnai RUR199iN Tankless Water Heater – Natural Gas

Rinnai RUR199iN Features and Specifications:
Fuel TypeNatural Gas
Efficiency0.93
Product dimensions22.1 x 14.8 x 33.9 inches
Flow rate11 GPM
Energy Star® certifiedYes
Read Verified Customers Reviews
Temperature rise/Groundwater tempMax flow rate (GPM)
68/42°F5.7
63/47°F6.2
55/55°F7
48/62°F7.8
43/67°F9
38/72°F9.8 (11 after parameter adjustment)
Pros and Cons
Built-in recirculation system, no “cold water sandwich” problem
A digital controller that allows to schedule the recirculation to align with usage patterns
Multiple venting options
Can be used with or without a dedicated recirculation line
Less draining water
It’s a bit pricey

Being the #1 most popular selling water heaters brand, Rinnai is very well known in the US and Canada. It provides some of the best performing and the most efficient tankless water heaters on the market.

That’s why Rinnai RUR199iN Ultra Series is a good candidate for first place in our rating of reviews of the best tankless water heaters. 

If not for the price, we’d only leave this one model. Rinnai RUR199iN is the best ultra-efficient tankless water heater with an astonishing flow rate of 11 GPM (take a look at the table above for more info). 

The killer feature of the Rinnai RUR199iN model is that it has a built-in recirculation pump. It eliminates a significant (and probably the only one) disadvantage that tankless water heaters are known to have. You don’t have to wait for hot water to get to your faucets or shower anymore. With this model, you get instant hot water on demand.

Here’s what owners say about it:

Owner's review
Kelly Widule
Kelly Widule
Mrs. Widule is a proud owner of Rinnai RUR199iN. She kindly agreed to share her personal experience with our readers
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We’ve had this unit installed for 2 years in our 2500 sq home with 3 baths and a family of 6. Works flawlessly. The only thing that’s bothering me a little is you do have to wait 5-10 sec more for hot water. But I believe a recirculation pump can solve the delay problem. Also, we live where the ground water temp is at 50 degrees or so which limits the flow rate of the system to 5-6 GPM in cold months. At worst, it may limit how fast I can fill the tub, but it doesn’t prevent operating multiple showers.

Usually, all tankless water heaters instantly heat the water but then the water needs to get delivered to the fixture.

For instance, your master bathroom is 80 feet from the heater. The unit fires up as soon as you open the tap, but you’ve got to evacuate all that cold water that’s in the line. 

With other models, you’d have to install an additional recirculation pump (which usually needs a dedicated return line), but with the Rinnai RUR199iN Ultra Series model hot water is instantly available in showers, sinks and kitchen appliances like washing machines or dishwashers. Because the pump is built in the tankless. You can push a button on the side, or use a motion detector, or a timer, or an app (Rinnai has several options) and as you walk into the master bathroom, the cold water circulates back at the tank and you get instant hot water in your shower. The good thing here is that you don’t have to drain that water anymore, it’s going back to the cold line.

  • You’re going green by saving more water
  • You’re saving more energy, since it has an astonishing 0.96 EF rating, meaning that for every dollar you spend on propane or gas, you get 96 cents back in hot water (compare it to old tank water heaters where you get only around 65% converted to hot water).
  • You’re saving money because you spend less on utility costs related to gas and water usage.  
  • You’re getting ENDLESS and INSTANT hot water. 

But with this level of comfort comes the price. Rinnai RUR199IN is expensive. You can check the current price on Amazon by following this link and compare the price to other models. 

But if you’re willing to pay the extra dollar for convenience and instant hot water on demand without waiting (sometimes up to 30-40 seconds), Rinnai RUR199IN is the way to go. It’s flawless. 20+ owners that we interviewed for these reviews can vouch for that. Plus you can read all Amazon reviews for this model here and make sure that most of the owners are really happy with it.

2. 🥈 Rinnai V65iN Tankless Water Heater – Natural Gas

Rinnai V65iN Features and Specifications:
Fuel TypeNatual Gas
Efficiency0.80
Product dimensions13.9 x 8.8 x 23.6 inches
Flow rate6.5 GPM
Energy Star® certifiedYes
Read Verified Customers Reviews

Rinnai RUR199iN is really a king of natural gas tankless water heaters. It is a good tankless water heater, it has great performance and it’s really powerful.

But what if you don’t need so much power? What if you could enjoy the quality of one of the most trusted American brands for a smaller price?

Well, you can. Rinnai V65iN is a perfect gas tankless water heater for a household with low to medium hot water demand.

I believe I’m not wrong when I say that Rinnai V65iN offers the best value for the money among other tankless water heaters. It’s almost three times cheaper than the previous model but delivers you 2.5 times more performance for the buck.

The average flow rate of 6.5 GPM is perfect for warmer climates where groundwater temperature doesn’t get freezing cold or/and smaller homes with 1 or 2 bathrooms and lower hot water demand. Six and a half gallons per minute is not a small number though. There are several sizes available on Amazon. So if you size it properly, it can easily handle two simultaneous showers (2.5 GPM each) or a shower and additional appliances, like dishwasher or washing machine. 

Overall, it’s a great quality for a lower price. 

3.🥉 Stiebel Eltron Tempra Plus 36 kW Electric Tankless Water Heater

Stiebel Eltron Tempra Plus 36kW Features and Specifications:
Fuel TypeElectric
Efficiency99.8%
Product dimensions16.5 x 4.6 x 14.5 inches
Flow rate7.5 GPM
Wattage36 kW
Voltage240 Volts
Read Verified Customers Reviews
Temperature rise/Groundwater tempMax flow rate (GPM)
68/42°F3.7
63/47°F4.2
55/55°F4.6
48/62°F5.2
43/67°F5.7
38/72°F6.7
33/77°F7.5

This is yet another good electric tankless water heater from a German brand Stiebel – Stiebel Eltron Tempra Plus 36 kW. This is a great alternative for houses with no gas lines or if you just prefer electric water heaters.

Tempra Plus series come in different sizes ranging from models with 1 GPM flow rate to 8 GPM in perfect conditions. Maybe in a lab 🙂 But in real life with the temperature rise of 50-60 degrees this model will provide a stable flow rate of 4 to 5 GPM of endless hot water

If you haven’t had electric tankless heaters you will probably need to make some adjustments in your electric panel. It requires 3 x 50 amps breakers and 3 x 6/2 AWG cables. 

This model can potentially use 150 amps, so make sure you have enough capacity

Stiebel Tempra Plus 36 is really tiny and can fit just about everywhere. 

When we prepared our tankless heater reviews, the most common question about this unit was if it can fill a bathtub with hot water. The answer is clear YES. 4-5 GPM is definitely enough for a bathtub. Moreover, we interviewed some owners from Missouri (with an average groundwater temp around 52-57 degrees Fahrenheit) and they’ve said that it could easily supply a house with 2 bathrooms, laundry, and a kitchen with hot water. With the air temperature in the 60-65 degrees, it was able to supply 2 showers running at the same time. There was some reduction in pressure though. 

It’s great for large homes in warmer climates and for smaller homes in the northern states.

Pros
  • Relatively low price
  • It has very convenient automatic controllers that adjust the pressure and temperature to meet the demand when several fixtures use hot water.
  • Due to small sizes, it saves a lot of space and can be installed near the point of use. It’s also very quiet, so it wouldn’t make any anoint noise
  • It requires NO venting
Cons
  • Since it’s an electric water heater, it may be difficult to install if you had no previous experiment
  • In cold climates, it performs much worse and consumes more energy. During dead cold winter when the groundwater temperature is below 50 degrees it can barely produce 3.5 GPM

4. Rheem Prestige RTGH-95DVLN Tankless Water Heater [Natural Gas]

Rheem Prestige RTGH-95DVLN Features and Specifications:
Fuel TypeNatual Gas
Efficiency0.93
Product dimensions18.5 x 9.8 x 27.5 inches
Flow rate9.5 GPM
Read Verified Customers Reviews
Temperature rise/Groundwater tempMax flow rate (GPM)
68/42°F5
63/47°F5.4
55/55°F6
48/62°F7
43/67°F7.5
38/72°F9
33/77°F9.5

Rheem is one of the most trusted American brands in the water heaters industry. We couldn’t make a TOP list without mentioning it.

We chose Rheem RTGH-95DVLN for its time-tested great reputation as a reliable workhorse for thousands of Americans. It is reported by the owners that Rheem RTGH-95DVLN perfectly does its main job of heating water without any significant issues. 

Now let’s get to the technicalities. This model comes in two options: indoor and outdoor. Both require a min. 11,000 BTU and can handle up to 199,900 BTU.

It shows 94% efficiency due to a stainless steel condensing heat exchanger (that’s how the heating element is called). It’s designed for both large and mid-sized homes, providing up to 9.5 GPM flow rate.

You would be surprised that such small and compact tankless water heaters can supply hot water to a big family of 4 to 6 members. The owners say that they tried using two showers, a whirlpool tub, and a kitchen sink all at the same time and the temperature never dropped.

It’s easy to install thanks to two PVC pipes direct venting system. You don’t need expensive stainless steel vent piping.

Some owners said that they experience some noise. It may happen because of improper installation. If you install the intake and exhaust pipes too close to each other, the intake may start sucking exhaust fumes causing the fan to run at its full capacity. It tried to clear the intake. So be careful about installing the unit. Or get professionals to do the job.

Pros
  • Endless and consistent supply of hot water
  • Vent system designed for PVC pipes
  • Compact sizes
Cons
  • Cold water sandwich problem (if used without a recirculation pump)
  • 120 degrees max temperature
  • Noise is a common problem

5. Rheem RTEX-13 Electric Tankless Water Heater

Rheem RTEX-13 Features and Specifications:
Fuel TypeElectric
Efficiency99.8%
Product dimensions4 x 9 x 13 inches
Flow rate3 GPM
Wattage13 kW kW
Voltage240 Volts Volts
Read Verified Customers Reviews
Temperature rise/Groundwater tempMax flow rate (GPM)
60/50°F1.5
44/66°F2
38/72°F2.5
33/77°F3

Up to this point, we’ve only reviewed gas/propane tankless heaters. They have great performance and a high flow rate. They’re very efficient and saves you money on energy costs for water heating. They may be used in every type of household, whether it’s a large 3-bathroom house with a big family enjoying a hot shower in all three bathrooms simultaneously or a mid-size house in the cold northern states where a couple wants to have the luxury of endless hot water on demand.  

But not everybody needs that high performance in their apartments, or condos, or RVs, or trendy tiny houses… You get the point. $3000+ in upfront costs for a 10 GPM tankless unit that will be used for heating water for one shower during all day might be an overkill.

So Rheem RTEX-13 comes to the rescue. It’s a good electric tankless water heater for single point-of-use or multiple applications. It’s best suited for apartments or small houses with low to medium hot water demand, where just one or two people are using hot water appliances. It’s also great for offices.

Rheem RTEX-13 is very easy to install, just follow the manual and you’ll get along.

For Rheem RTEX-13 you’re going to need to have 1 x 60 amps power breakers. 6 AWG wire size is recommended. If you’re not familiar with wiring details, consider getting a quote from professionals.

It is one of the several units from the Classic Series. If the maximum of 3.8 GPM in Rheem RTEX-13 is not enough, you can choose a different option. The model with the highest performance is Rheem RTEX-36 which, according to Rheem, can provide impressive for an electric tankless water heater maximum of 8GPM, if you live in the south. The lower the temperature of the groundwater in your location, the lower the flow rate will be. Although the manufacturer claims the maximum flow rate is that high, the actual one will probably be around 3 GPM for RTEX-13 and around 6 GPM for RTEX-36.

If you want to use low flow rate models like Rheem RTEX-13 in your house, but you’re afraid that they won’t be able to handle your hot water demand, consider installing low flow showerheads and aerators on as many fixtures as possible. It will reduce your actual flow rate without losing the pressure. And with less GPM demand you’ll need smaller and cheaper tankless water heater.
Pros
  • Very easy to install
  • Good choice if you’re on a low budget
  • It has compact sizes and could fit probably everywhere
  • Great value for the money
Cons
  • One unit can’t supply the whole house with hot water (you can buy several units though)
  • Without recirculation pump, it has a cold water sandwich

7. Ecosmart ECO 18 Electric Tankless Water Heater

Ecosmart ECO 18 Features and Specifications:
Fuel TypeElectric
Efficiency99.8%
Product dimensions3.6 x 14 x 17 inches
Flow rate4.4 GPM
Wattage18 kW kW
Voltage240 Volts Volts
Read Verified Customers Reviews
Temperature rise/Groundwater tempMax flow rate (GPM)
68/42°F2
63/47°F2.1
55/55°F2.5
48/62°F2.9
43/67°F3.2
38/72°F3.7
33/77°F4.4

This is probably the best electric tankless water heater for medium-sized households. For such a low price it provides an astonishing real 4.5 GPM flow rate. In northern states, it can achieve up to 2.3 GPM. And that’s not just naked specs. The owners we interviewed and people on Amazon with verified purchases also say it can handle that amount of hot water without losing much water pressure.

 It requires two 40 amps breakers and 2 x 8 AWG wires and a 240 V circuit.

If you live in the southern states you can be sure that this unit can easily handle a mid-size household with two showers plus maybe a laundry used at the same time. But as always, it all depends on the temperature of the incoming water. The lower the temperature, the more the tankless heater has to work, the lower the flow rate it will be able to provide hot water at the set temperature.

If you’re not sure about the capabilities, check out other Ecosmart models with greater performance, like Ecosmart 27 which provides up to 6.5 GPM.

Pros
  • It has a self-modulating system that adjusts heat to the current demand. It will not heat the water more than required.
  • It supports a remote which gives you control overflow temperature
  • The unit got almost 2 thousand positive reviews on Amazon
  • It’s very quiet and starts working slowly
  • Lifetime warranty
Cons
  • You can only be qualified for the warranty if the unit installed by professionals, which sometimes is not cheap at all
  • If you don’t have enough circuit load capacity (200+ amps) it may cause some trouble

How to Select The Right Tankless Water Heater: Buying Guide

If you’re new to all this stuff, chances are you’re very confused right now and don’t even know where to start from. And you’re probably asking yourself: “what should I look for when buying a tankless water heater”? 

Easy peasy! Just follow this easy 3-steps guide and find out how to choose the right tankless water heater for your needs.

Step 1: Decide which fuel source you are going to use

The first thing you need to know is that there are 4 types of tankless water heaters by fuel source: natural gas, electricity, propane, and solar power. The last one is very new and expensive right now. So we’re only looking at those three.

Every household circumstances are different. I can’t tell you exactly which fuel source is better for your situation. But here are some factors to consider when making this decision:

  • Is there a convenient natural gas source available at your house? Residential tankless water heaters may use up to 199,000 BTU in power. You need to make sure that your system can handle the load. But keep in mind, that 199,000 BTU is the peak number, so use it as a maximum borderline.
  • Do you have enough electric service capacity? If you’re considering a whole-house electric tankless water heater, your service should be about 150-200 amp and have enough space for breakers in your panel. The requirements for point of use tankless water heaters are much much lower though.
  • Installation cost. Depending on your previous answers, installation costs may vary a lot. If there is some plumbing or electrician work to be done, you may need to call a professional. Otherwise, you can always do the installation yourself. Tankless water heaters are usually relatively lightweight and easy to install. With some DIY skills and an installation guide, you can easily do it yourself. 
  • The difference between electricity costs and gas costs in your area.

Make some calculations and decide what works for you. When you make your decision and choose between natural gas, electric, and propane tankless water heaters, you’re ready for step #2:

Step 2: Determine the right size of a tankless water heater

Tankless water heaters are available in many different sizes across all brands.

The biggest size you can have available for residential models is 199,000 BTU. 

Above 200,000 BTU you’re going to need plumbing license called a boiler operator license

Sizing a tankless water heater is very different from sizing a tank storage water heater since you can’t run out of hot water. But you do have to consider the peak demand.

If you’re planning to use several appliances that use hot water simultaneously or you need to be able to use more than one shower at a time, you’re going to need a more powerful unit.

The whole process of selecting the right size comes down to three steps:

  1. Determine the peak hot water demand. How much hot water are you going to use at the same time (in gallons per minute)? 
  2. Determine the worst case temperature rise for your region
  3. Select the model that satisfies the requirements

That’s all 🙂

Now, you may be asking how to do all that. If you’re still wondering what size tankless water heater do you need, we have a detailed guide about that and a sizing calculator to help you. Just follow the link.

Step 3: Choose the brand

Now that you know how big your tankless water heater should be and you’re ready to pick the model, you may notice that there are several models from different brands that suit your requirements.

How to decide which one to choose?

You may ask your local contractors, but they often recommend different brands that they’re used to work with or get paid by. And they make it even harder to choose.

We asked one of our experts. And here are a couple of insights he agreed to share with us:

Professional Opinion
Frank J. Cowles
Frank J. Cowles is a NY-based HVAC professional with 20+ years of experience in the industry
Ask Question
For many contractors, the brand they’ll recommend is based on what they can get parts and support for. Myself – I prefer Rinnai and Bosch. Rinnai has people on call – even on weekends – to offer contractors support on troubleshooting. Bosch has higher efficiency and more adaptive intelligence in its operating software than most. Are Navien, Nortz, or the other bad units? No. Navien supports their products very well. The others vary based on brand. In the end – buy your contractor. If you feel comfortable with him and know he’ll be there when you need him – go with the unit he recommends. One word of caution – beware of those that do not own or use a combustion analyzer. The 90%+ plus unit MUST be tested and tuned to run properly. Bosch has that as an internal function done as part of commissioning. Most other brands do not and will fail early if not commissioned properly.

As you can see, there’s no one best of all brands. Each brand has its own strengths and weaknesses. 

But you still need to choose one, right? Personally I would recommend these: Rinnai for natural gas, Ecosmart or Stiebel for electric, and Rinnai or Eccotemp for propane. That’s why they’re on our list of best tankless water heaters. 

Just go to our comparison table and simply choose the model using our checklist:

  1. Filter them by fuel source
  2. Check if the model can handle your hot water demand at the temperature rise at your home (we have convenient tables for this under each individual review).
  3. Check if the price satisfies you and buy the unit.

Pros And Cons Of Tankless Water Heaters

Tankless water heaters are great! But I believe that customers should make informed decisions. So here are some quick facts about the advantages and disadvantages. Find out what is good and what is bad about tankless water heaters:

Pros of tankless water heatersCons of tankless water heaters
Higher efficiencyRequire annual maintenance
Compact sizesMay require prior setup work
Endless hot waterLimited flow rate
Long-term energy costs savingHigher upfront costs
They last longer 
Environmentally friendly 

[Advantage]: Tankless water heaters are more efficient

A tank may heat and reheat the water even when you’re not at home. 

Tankless water heaters operate strictly on-demand. This means you only heat water when you need it. When you don’t need it, the unit does not consume any energy. 

[Advantage]: Tankless water heaters save space

Unlike big tank water heaters, tankless units do not take a lot of space. You just mount a little box on the wall or under a sink and you’ve plenty of space left for your utilities.

[Advantage]: Endless hot water

When the demand is high, tank water heaters may run out of hot water, leaving you in the cold. But tankless water heaters heat water as it goes through the pipes, giving you an endless supply of hot water for the whole family.

So if you like those 30-minutes long showers, tankless water heaters are your best choice. 

[Advantage]: Tankless water heaters save money by reducing energy costs 

Of course, if you don’t have a large house or several kids who use the hot water heater a lot, you may not see a ton of money saved in your natural gas bill. But it will still go lower!  Because you are only using hot water when you wash dishes, clothes, or take a shower. You don’t have it all on all the time. And you don’t have a huge 50-60-75 gallons tanks constantly being heated up. 

The savings may not be big month to month, but over time you’ll see how a tankless water heater is a great investment of your money.

[Advantage]: Tankless water heaters last longer

Tankless water heaters usually last twice as long as your typical tank water heaters. And if you use a water softener or just have soft water it may serve you up to 3 times longer. The average lifespan of a tankless unit is around 20-25 years. 

[Advantage]: Tankless water heaters are environmentally friendly

You’re drastically reducing CO2 footprint of your household if you’re using tankless water heaters. Since they heat water on demand, they use less fuel to heat the same amount of water. 

[Disadvantage]: Tankless water heaters require annual maintenance

The problem with tankless water heaters is that they require maintenance. 

The maintenance cost really depends on the water. The harder it is the more maintenance it’s going to require. 

If you use well water and you have a family of 3 to 5 kids and you use hot water a lot, you’d probably need to flush your tankless once a year. 

It’s relatively easy. You just get a solution pumped through the burner system. It’s going to remove all that calcium deposits from hard water. 

If you have 2 to 3 people in your house, you’d need to do the procedure once every 2 to 3 years.

You can make it work longer without flushing the system if you use a water softener system or you just have soft water. This way you may never even need to flush the water heater.  

Maintenance is VERY easy with modern tankless water heaters. Many of them have a little LCD screen where you can see the output temperature of the water. When something is wrong or broken, it shows an error code which you can google online, or call a plumber, or call the manufacturer. It’s really handy and you don’t have to worry about ANYTHING. 

[Disadvantage]: They may also require prior setup work

If you live in an old house, your gas line or electric service may need an upgrade if you decide to go tankless. Sometimes costing you more than you can save. (Spoiler: the convenience of endless hot water on demand worth it!)

[Disadvantage]: They have limited flow rate

My clients almost never remember to pay attention to this parameter when they choose a tankless for their home. But it may become an issue for you. Especially in winter if you live in a colder climate region. The problem is that when the flow is too low, the unit may not be activated and you’ll get colder water. It’s almost never a thing for modern (and more expensive) tankless water heaters because their minimum flow rate is at 0.26-0.3 GPM. But if you choose to buy an older model you may end up with cold water when you want to wash your hands.

[Disadvantage]: Tankless water heaters cost more than storage tank

Tankless water heaters are usually more expensive than tank-type water heaters. But it’s a great investment if you count the costs over time.

They’re available in a wide range of prices. It really depends on the type and size of a tankless water heater. The bigger you choose, the more expensive it will be. You really pay for what you get.

If a tankless unit seems too expensive for you, it might be because it already has a special feature, like a built-in recirculation pump or smart technology. You can choose a cheaper option, but are you really sure you won’t pay more in the future?

For example, a built-in recirculation pump solves the problem of a cold water sandwich and supplies you with instant hot water. It decreases the amount of draining water and reduces your water and energy bills.

A few thousand dollars right out of the pocket is never cheap. But it’s not that big of a deal when you compare it to overtime cost of having two or three tank water heaters.

Additional requirements for electric units

Before choosing a tankless water heater find out if your home has the necessary electrical requirements to support the unit you need.

Since they have greater voltage requirements, you may need to have a qualified install upgraded breakers and thicker gauge wiring to handle an increase in power.

  • How many amps do you need?
  • What size breaker do I need? 
  • What kind of tankless water heaters do I need? (by Power Source)

Frequently Asked Questions About Tankless Water Heaters

💲 Is a tankless water heater worth it?

Although the upfront costs for buying a tankless water heater is higher, it is more efficient than storage tank water heater, uses less energy and saves you up to $100 on energy costs on average annually. So yes, I think tankless water heater totally worth it.

🤔 Can a tankless water heater fill a tub?

Yes, a tankless water heater can fill a tub. But you should properly size your system. If you buy a too small tankless water heater it would take ages to fill a tub, since it can provide only so much gallons of hot water per minute.

⌛ How long does a tankless hot water heater last?

Newer models of tankless water heaters have a life expectancy of more than 25 years. Compare it to 10-15 years for storage tank water heaters. If you descale your tankless water heater every couple of years, it can last even longer.

❓ Do tankless water heaters run out of hot water?

Tankless water heaters never run out of hot water because they heat it as the water flows through it.

💰 How much does it cost to install a tankless hot water heater?

The cost totally depends on your contractors. On average it costs between $1000 and $2000 to install a tankless water heater. But the installation process is really easy. With some DIY skills and the installation guide, you can have it installed in several hours or a day.

🏠 Does tankless water heater increase home value?

According to Zillow, homes with tankless water heaters are sold for 4 percent more than their expected value. So, the answer is yes, a tankless water heater increase home value.

🔧 Do tankless water heaters need maintenance?

Tankless water heaters require annual maintenance, which means that it should be done once a year. If you have hard water at your home, tankless water heaters may require maintenance every 6 months. Rinnai have a nice feature for it. It sends an error code when the tankless water heater needs to be flushed due to scale build-up, and shuts down to prevent damage.

🤑 Do tankless water heaters really save money?

Although the initial costs are higher than storage tank models, tankless water heaters save money in the long run. According to the U.S. Department of Energy, tankless water heaters can save at least $100 per year.

2 thoughts on “Best Tankless Water Heaters in 2020: Reviews and Rating”

  1. This is THE most comprehensive and honest guide I’ve ever read. Thank you for this.

    And since I now see you’re an actual expert and not some esl student, I have a question.

    What tankless model would you suggest for a single bathroom house. There’s only my wife and myself.

    • Hey Jim!

      I’ll have to ask for more information. I can’t give any specific advice just based on the number of family members.
      The only thing I can say for sure is that you don’t need to buy a big one.
      If you want natural gas fueled tankless, take a look at Eccotemp i12-NG.
      If you’re better off with an electric powered tankless unit, I’d suggest Ecosmart ECO 11 or ECO 18. It totally depends on your requirements.

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