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WHAT IS A TANKLESS WATER HEATER?
Tankless water heaters are a major innovation in the field of home water heating. Unlike traditional tank heaters, which heat and store water, tankless heaters heat only the water that you need. As a result, they are sometimes known as ‘point of use’ or ‘on-demand’ water heaters. Because they heat only the hot water required, they are far more energy-efficient than traditional tank-based heaters. This makes them an attractive addition to most new homes.
Knowing which type of tankless heater to get, however, can be tricky. This guide will walk you through the different options so that you can make the most informed decision. For more general information on this type of heater, go to our tankless water heaters page and to learn more about the costs involved with purchasing and installing them, see our average cost of tankless water heaters page.
To work out our winner, we compared market-leading models from a variety of different brands. The key factors we looked at were:
The best tankless water heater is the one that performs the best across all of the different facets. After all, the best option for you and your family is the one that combines all of the above qualities.
OUR OVERALL WINNER
The Rheem Performance Platinum 9.5 GPM model ticks all the boxes. It provides more than enough flow rate for a family of four, providing a generous 9.5 GPM. While the 11 GPM model may be tempting because of its higher flow rate, it does come with a much higher cost. Moreover, 11 GPM is more than many families will require – so the extra cost may not be all that beneficial. The Rheem 9.5, therefore, hits the sweet spot of price and efficiency.
On top of all this, the Rheem brand is a well-known and well-respected brand within the tankless heater market. This results in a reliable product. Unlike other models, there’s no lag from turning the faucet on to hot water emerging, meaning you and your family get the hot water you need (and pay for).
QUICK COMPARISON CHART
Platinum 9.5 GPM
|Rinnai 11 |
Platinum 11 GPM
|Flow Rate |
@ 35 Degree F
|Max temp (F)||140||140||185||140|
|Min temp (f)||85||80||98||100|
BEST OVERALL TANKLESS WATER HEATER
Rheem Performance Platinum 9.5 GPM Natural Gas High Efficiency Tankless Water Heater
If you want a tankless water heater that does its job reliably and efficiently then this is the one for you. Packing a 9.5 GPM flow rate, you can have 2 showers running simultaneously and still have hot water in the kitchen. The Rheem brand name means you can trust this machine to work well for the better part of a decade (if not longer), which helps to offset the initial cost.
Put simply, this is the tankless water heater you buy if you want one that ticks all the boxes. It keeps your water warm at a decent price point, heats the water efficiently to a high temperature, and won’t let you down. This was our clear winner.
The Rheem Performance Platinum 9.5 GPM costs $1,299.
Rheem Performance Platinum 9.5 GPM Specs:
What People are Saying:
“I installed this unit in a single family home with two baths and a laundry. The product is first class and the directions are detailed and excellent – but you better know your stuff.” – Mike, Amazon reviewer
“I’ve had this installed for 6 months now and I’m glad I did. It took about a day to install. Saves space. Operates quietly and definitely has saved me from having to get oil deliveries. Easy to maintain. Only a couple filters and an annual check from a professional. It also lowered my total water usage for house. For anyone who has an older system like I did will benefit from doing this upgrade.” – Home Depot reviewer
BEST ENVIRONMENTALLY-FRIENDLY OPTION
EcoSmart 27 kW Self-Modulating 5.3 GPM Electric Tankless Water Heater
One of the key features of the EcoSmart models is the fact that they are self-modulating. This means that they adjust the amount of energy used based on the water you use and the temperature you desire. This effectively means that no energy is wasted, and it is a key factor why this brand scoops our award for the best environmentally-friendly option.
However, the real headline factor is its energy efficiency – the EcoSmart27 operates at 99.8% efficiency, meaning the electricity you pay for is almost all used to heat the water. This creates the additional benefits of lowering usage cost and generally benefitting your environmental impact. This model operates at the sweet spot where self-interest meets altruism. So, you’ll be doing the best for the planet and your wallet, and what’s not to love about that?
The EcoSmart 27 kW Self-Modulating 5.3 GPM Electric Tankless Water Heater costs around $489.
EcoSmart 27 kW Self-Modulating 5.3 GPM Specs:
What People are Saying:
“Bought this water heater to replace an old tankless one. It is easy to assemble. Once turn on, we have hot water in seconds, faster that the old one. The temperature adjustment feature is awesome, and more energy efficient.” – Home Depot reviewer
“Overall, I give this unit 5 stars. Price, reliability and technical support are right up there. The unit comes with a lifetime warranty when professionally installed. Cleaning and maintenance is accomplished with a Phillips screwdriver, no more pipe wrenches and fiberglass insulation to contend with.” – Dave, Amazon reviewer
BEST HIGH-END OPTION
Rinnai Super High
Efficiency Plus 11 GPM
The Rinnai 11 GPM represents the future of tankless water heaters. Increasingly, as we build smart homes, we demand more and more from our appliances. This Rinnai model delivers. It comes with WiFi compatibility, meaning you can sync it with your phone and even your smart speaker to build a network of devices in your home.
Aside from the technical wizardry, the Rinnai delivers a truly powerful 11 GPM, with a UEF of 0.93. This means that it won’t let you down even in the most high-use households. Of course, all of this doesn’t come cheap – so you’ll be shelling out over $1,600 for this option. However, if you’re prepared to spend the cash, this model is a game-changer.
The cost of the Rinnai Super High Efficiency Plus is around $1,660.
Rinnai Super High Efficiency Plus Specs:
What People are Saying:
“I installed this water heater in my house and we have plenty of hot water for two showers, dish washer, and washing machine. Our water comes from a water tower and it is pretty cold during the winter. It heats it up pretty fast.” – Shawn, SupplyHouse reviewer
“Professionally installed in less than half a day. Works well and endless hot water takes about 12 seconds to start receiving.” – Home Depot reviewer
BEST LARGE FAMILY OPTION
Rheem Performance Platinum 11 GPM
Natural Gas High Efficiency Indoor
Recirculating Tankless Water Heater
The Rheem 11 GPM packs some serious power, albeit with a serious price tag. If you have a large family, or simply want endless hot water in high volumes, this is the model for you. 11 GPM is an almost unbeatable flow rate and will ensure that you can have multiple showers and appliances running at the same time without a second thought.
What makes this our best large family option is the flow rate, of course; however, the Rheem has a variety of classy touches.
For example, it’s designed to be compatible with your existing plumbing and gas systems, making conversion a breeze. A UEF of 0.94 doesn’t hurt either, although it may be a while before you recoup the $1,400 cost.
The Rheem Performance Platinum 11 GPM costs around $1,399.
Rheem Performance Platinum 11 GPM Specs:
What People are Saying:
“Love having enough hot water finally! A little tricky to install and make sure you call your gas company to check that your meter is big enough.” – Home Depot reviewer
Ultimately, the tankless system you require in your home is dependent upon the following:
These four factors will shape the specific requirements of your tankless system. However, this guide has suggested the best option across a range of criteria.
The Rheem 9.5 is the best option across the board and will give you hot water when you need it. After all, the joy of a tankless system comes from an appliance that you don’t need to think about. There are cheaper options out there, but can you put a price on a warm shower on a cold morning? Or not having to call in a plumber in the depths of winter?