Best Tankless Water Heater Reviews

best tankless water heater reviews

Tankless Water Heaters have been used for decades in Europe and Asia and are gaining popularity in the US everyday. Unlike conventional heaters tankless water heaters don't store hot water. When water is needed the flow of water through the device fires the burner for instant hot water. Tankless heaters are more expensive but the benefit of not having to worry how many people have showered already when you need to soak your sore muscles at the end of a long day is priceless!

There are many pros and cons with every appliance purchase but if you read all of the tankless water heater reviews we feature here you will be one step closer to making a well-informed decision. Most people who have installed a tankless unit in their homes love it, the heaters are safe, convenient, efficient, have a long life, take up very little room, and provide clean, piping hot water on demand.

Keep reading for real, verified customer reviews, product reviews of the top tankless water heater brands, and lots of tutorials and tips to help you become comfortable with the lingo and workings of the tankless water heater.​

rheem tankless water heaters reviews
Rheem Tankless Hot Water Heaters

Rheem Customer Reviews 

Works great, easy to increase temp, now that winter is here, and endless hot water. This mid size unit is perfect for our needs. I will never by another tank unit again.

​I put one of these rheem tankless units in - and it WORKS! sweet! I love it! I had to turn the water temp down to about 3/4 up- it was too hot all the way up. My bills have never been this low!

Benefits of Choosing a Tankless Hot Water Heater

    • Energy Efficient- 30% more efficient than a conventional tank hot water heater. If you like the idea of being environmentally friendly tankless is for you. You will reduce your carbon footprint significantly with an on-demand water heater.
    • Clean Water: No storage tank that accumulates rust and scale. When a traditional water heater holds water in its tank any sediment in that tank will be flushed into your water pipes. This is especially true if you live in a hard water area. 
    • $$$ Savings: Monthly savings of up to 40% off your heating bills. The biggest downside to a conventional water heater is that it spends all day heating and reheating the water that's sitting in its tank. That's a huge energy waster!
    • Convenient: Continuous hot water, no more scheduling of bath times! The best benefit of a tankless unit is that if three people have already showered, you still can too! Just get an instant heat unit with a high enough flow rate and if you live in a cold climate go with a gas unit and you'll be a happy camper.
    • Long Lasting: Tankless heaters last twice as long as conventional water heaters. Traditional water heaters have a lifespan of 10-13 years while a demand unit will last over 20 years.

rinnai tankless water heater reviews
Rinnai Tankless Hot Water Heaters

Rinnai Customer Reviews 

​     My husband and I installed this ourselves. We went from an electric 50 gallon water heater to this. I can honestly say I love the heater. I do not have to worry about saving any hot water for my husbands shower because there is a never ending supply. I will never go back to a tank system.

​     Initially, I was skeptical. Now that the replacement Rinnai is installed, we have plenty of hot water. This thing will easily keep up with two sinks and a shower running simultaneously with winter supply water temperatures.

Choosing the Best Tankless Water Heater Brands

There are many top rated brands on the market today that offer propane, natural gas and electric tankless models. Luckily, there is a fairly wide range of prices available. Of course, with a cheaper price you will probably be giving up some quality or some advanced features. A good rule of thumb is when you decide to invest in a tankless unit you should look at it as an investment rather than looking for the cheapest price. However, there are always deals to be had and even a top rated, five-star reviewed tankless unit can be found at deeply discounted prices. Check out our Ultimate Guide to Tankless Water Heaters for the best price guide.

      • Rinnai – These heaters get great reviews online. Their advanced technology make them sought after units. There are good customer reviews on the RL75iN, RU98IN, RL94iP, V65EP, and the V65IN. Prices are $600-$1,500
      • Bosch- Offers mini-tank, whole house, and tankless units of many styles and specifications. Bosch has been around a long time and has decent reviews overall, some great, some good. Great ratings can be found for the Ariston series, the GL 2.5, GL 6, and the GL 4S. Prices run under $100 to over $1,000
      • EcoSmart- This is a great lower end brand. The reviews come back really good overall with multiple four and five star products and the prices are lower. Top electric tankless models from Ecosmart are the ECO 27, ECO 11, ECO 18, ECO 24 and the ECO 8. From $100 to $600.
      • Rheem – is one of the top brands and has multiple four and five star reviewed products. Its series includes propane, natural gas, and tankless electric heaters, condensing units, indoor and outdoor installs. Many of the Rheem heaters have top ratings like the RTG-84DVLN, RTE 9, and RTGH-95DVLN. The RTE 13 is the bestselling tankless on Amazon! Prices are $200-$1,300
      • Takagi – Is a pioneering brand in the water heater industry. Several of Takagi's heaters are holding 5 star reviews on Amazon. The best tankless gas units are: TH3DV-NG, T-H3-DV-N, T-K4-OS-NG, T-D2-IN-NG all have awesome reviews.
      • Noritz – Offers the high efficiency ecoTOUGH™ line, the durable ProTOUGH™ line and the cost effective ValueSolutions line. The best gas tankless water heaters they offer are the NR50-OD-LP, the NR71-SV-NG, and the NRC98-DV-NG.

noritz tankless water heater reviews
Noritz Tankless Hot Water Heaters

Noritz Customer Reviews

​You do get what you pay for! THIS WATER HEATER IS AMAZING!! I LOVE IT!!!

​Look no further ... Costs, quality and efficiency... This is the best in this technology.

​Efficiency, dependability and great warranty!

What Size Tankless Water Heater Do You Need?

To determine the size of the tankless hot water heater you need, you’ll need to calculate how much hot water you’ll need at one time, which is called the flow rate. Flow rate is measured in gallons per minute (gpm). The table below provides typical flow rates for typical household hot water applications.

 ​Figure out what would be the maximum flow you would typically need. As an example if you would like to be able to have three showers going each morning and the kitchen faucet running for washing breakfast dishes you would need a maximum of 11 GPM. If you install low flow faucets you could get away with a much lower max GPM.​

  • Washing Machine



    Bathroom Faucet

    Kitchen Faucet

    1.5 to 3.0 GPM

    1.0 to 2.0 GPM

    1.0 to 2.5 GPM

    0.5 to 1.5 GPM

    3.0 to 7.0 GPM

     You will also need to consider the average temperature of the water coming into your home. Most tankless units can handle a 70 degree rise at 4 GPM gas powered and 2 GPM for electric powered.​ This means to get 120 degree water, which is what most people will want for things like laundry and dishwashers your incoming water needs to be 50 degrees on average. 

​     If you live in a cold climate that won't happen so you will have to take that into consideration when choosing a water heater. This guide shows some average temps for various US cities inlet water.

Top 4 Best Reviewed Tankless Water Heaters


RTE 13

Amazon #1 Bestseller

  • Electric Powered
  • 4 GPM Flow
  • 10 Year Warranty
  • Energy Star Certified




7th Bestseller on Amazon

  • Natural Gas
  • 6.6 GPM Flow
  • 10 Year Warranty
  • Energy Star Certified


Rinnai RU80IP

5 Star Customer Rating

  • Propane Powered 
  • 8 GPM Flow
  • 10/5/1 Warranty
  • Max Energy 0.94


Stiebel Eltron

Tempra 20 Plus Model

  • Electric Ventless
  • Whole House Model
  • 3 Year Warranty
  • 8 GPM Max Flow


​Check out this YouTube video on the basics of tankless units, it gives a nice overview for those folks who have not had much experience with this style of heating unit.


Hi, I'm Frank, a plumber by trade. Since retiring I decided to start a website to help people find the best home water heater reviews. I like to read and learn and I hope my curiosity about water heaters will help people to find the best one for their home and family. You can find me at Twitter and on Google+


  • Pat Emard says:

    Hi, I am researching water softeners. I have a noritz on demand system and installed a descaler. Interested in your opinion re Ryan’s or culligan, as they seem to have highest level of satisfaction, but are pretty expensive—are they worth it? Also info on reverse osmosis system for drinking water?
    Side issue: any advice on any re circulation pumps that work with Noritz? Seems warranty isno good unless I install a very expensive system!
    Hope I am not too much of a bother!
    Thanks for any advice, Pat in Santa Cruz, ca

    • Frank Van Zuuk says:

      Culligan is a good system with a good rating but you are correct about the expense, I haven’t any experience with Ryan’s. You could consider installing the softener yourself although in many cases that voids the warranty. You could also buy it yourself and have a pro do the install which is a “best of both worlds” situation. There are many high quality water softeners out there, check out the link I suggest it may just give you a few ideas.

      I have written several reviews on water softeners you might find helpful here:

      In particular check out the review on the best reverse osmosis systems, in my opinion you can’t go wrong with an iSpring or if you want top of the line a TapMaster. In a nutshell the RO unit will be more of a point-of-use system on your kitchen sink and maybe your ice maker. If you go 6 stage with hard water filter it will remove hard minerals. If you are thinking of a whole house water softener you could go 5 stage on the ro unit and save some $.

      Finally, you are correct on the re-circulation issue. Noritz recommends only a couple of pump brands ($500+) and any others will void the warranty. There isn’t any way around this as far as warranty issues go, sorry I couldn’t bring better news!

  • Andy F says:

    Rannai tankless water heater leaking from bottom. Unit installed 10 years ago / 13 years old according serial number. Can hard water cause unit to fail sooner? Also error code 11 won’t produce hot water because furnace will not fire off any more? Is this unit done?

    • Frank says:

      At 13 years old the unit should still have some life in it. However, that said the typical life of tankless units is double that of a tank unit, so you are getting towards the upper range of your tankless units life and as we all know the older things are the more problems they encounter. If you do have hard water issues that could definitely contribute to your tankless unit’s problems. Hard water will leave a build-up of calcium and magnesium deposits that over time will clog pipes and plumbing. I would say that given the number of issues you are having the best bet is to call in a pro to tear the unit apart and have a look. You might be looking a enough of a repair bill that it just makes sense to invest in a new unit that will not be bringing in the plumber every few months.

      Hope this helps, good luck Andy!

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