Best Tankless Water Heaters & Brands

The popularity of tankless water heaters is at an all-time high, and for a good reason. If you have done any research into these systems than you already know what you stand to gain by adding one to your home or property. Aside from their ability to provide a seemingly endless supply of hot water, on demand no less, these systems save money on both water and heating bills.

Tankless hot water heaters are becoming more popular, forcing manufacturers to step up the pace in producing them, which isn’t necessarily a good thing for consumers. Not all tankless water heaters are created equal. This is why we thought we would share some of our favorites that are tried and tested by actual homeowners, rather than clever company marketing.

Tankless systems are an investment, so let’s make sure we are making the right purchases from the start by arming ourselves with the best information to find the best tankless water heaters.

The Tankless Water Heater – Defined

If you’re new to the tankless water heater phenomenon, then it might be helpful to learn a little more about how they work. While standard water heaters collect and heat water, so it’s ready to use, a tankless system is no bigger than a suitcase (typically) and heats water on demand.

A tankless water heater uses a heating element, either via gas or electricity, to heat water as it passes through the element and to your faucet. The heating element is referred to as a heat exchanger which you might guess, transfers heat from one source to another.

Some systems are made to be placed in a basement (or similar space) and control water for the whole house. Others are made to be placed at plumbing sites, for example, in a bathroom cabinet under the sink as a “point of use” option.

Before You Buy a Tankless Water Heater

There are a few considerations you’ll want to calculate before you decide on what tankless system to go with. These include energy rating, flow, temperature rise, and size of your system.

  • The Energy Rating – Every appliance these days seems to have an energy rating, and tankless systems are no different. This can be helpful to consider since not all tankless water heaters are built to be efficient. Known as the (EF) rating, the energy factor is a rate determined by how much a single unit of fuel is used to heat a specific amount of water. The higher that number is, the more efficient the tankless water heater will be.
  • Flow Ratings – This rate relates to how much water will be heated as it enters the home. This depends wildly on how much water, and how many people, your system will need to serve. Talk to a professional (a free consultation) about what this might mean for your particular property before making your purchase online.
  • Temperature Rise – Simply put, the temperature “rise” is the difference between the water entering your home and the desired temperature you want to set your hot water to inside the house. Some units will be able to handle this differential better than others.
  • Size of the Tankless System – When you know the flow and temperature rise, you will better understand what size tankless water heater you’re going to need. Factor in the number of people who will be using the system and how they use water. The result of those considerations will help you determine the right size unit for your property.

1. Rinnai RUC98iN Ultra Series Twin Pipe Natural Gas Fuel Tankless Water Heater

One of the unique features of this Rinnai tankless water heater unit is that it takes condensing technology and turns it into a more efficient hot water output. The company says that this new unit improves energy efficiency in a 120-volt package that weighs 82 pounds. This is a residential style unit but can be used for commercial applications, with a 9.8 gallons per minute flow rate.

Rinnai is a pioneer in the tankless water heater space, and they have been in this industry for many years. Their reputation among customers and those within the industry is strong when it comes to service and continued development. We consider this unit as one of the best tankless water heaters out in the market.


  •  The unit can be installed on your own using the in-depth manual. Some people reported that it was a pretty straight forward process with very few hiccups during installation.
  •  The longevity of this system is often reported to be positive with few reports of systems not working correctly.
  •  Gas and Electric options available; most people who went with the gas option report better savings than the electric unit.
  •  Few maximum load issues are reported with this system. Users say this unit is able to keep up with their entire households (including teens) without having to go without hot water.
  •  Most poor experiences come from customers not feeling they get the best customer support from the company.
  •  Other poor ratings come from users feeling like it takes a long time for the hot water to reach the faucets.

The Specs

  • Product Dimensions – 10 x 18.5 x 26 inches
  • Type – Twin Pipe / Ultra
  • Option – Concentric or PVC venting
  • Energy Source – Gas or Electric
  • Energy Factor – 0.0 to 0.96 Energy Factor
  • BTUs – 199,000 max
  • Certifications – Clear NOx emissions

2. Stiebel Eltron Tempra Plus 36 kW, Tankless Electric Water Heater

The Tempra® Plus was designed to handle maximum load using superior technology without the need for venting. The company says the Advanced Flow Control adjusts the flow of water to eliminate temperature fluctuations that standard water heater users complain about. This reflects in having a constant water tempter without making a lot of adjustments, for example, in the middle of your shower.

This is a German company that excels in the area of alternative heat sourcing, which has been working on creating and perfecting the tankless water heater for close to 90-years. The system runs on 240-volts and weighs only 19 pounds.


  • Users report that the unit is highly efficient and quiet.
  • Those who opt to install it on their own spent between three and six hours on the project.
  • The additional cost to install ranged from $100-$400 dollars as opposed to thousands from install quotes.
  • People suggest making sure you have the right electrical panel and space to add this unit to your panel before purchasing.
  • Those who use it with well water were happy about how well the unit heated that water.
  • Faulty units failed after just a few months to two years.
  • Other users report having water pressure issues with this system.
  • Some users report that water didn’t get hot enough for them and had to return it.

The Specs

  • No venting required for this tankless water heater
  • Digital temperature gauges
  • Dimensions – 14.52″ x 16.54″ x 4.61″
  • Weighs – 19 pounds
  • 7-year leak protection warranty
  • 3-year parts protection warranty

3. Bosch Electric Mini-Tank Water Heater Tronic 3000

This unit is considered to be a point-of-use option as it’s smaller in structure so it can fit horizontally or vertically under a sink /cabinet. This unit is ideal for small spaces as it’s compact in structure, lined with thick foam for efficiency and constructed with a glass-lined tank. This system comes in 2.5, 4, or 7-gallon options.

This tankless system is designed to lessen “lag time” from hot water traveling from a water heater to the actual point of use, such as a showerhead or faucet. Temperature ranges are 65-145°F max. Pressure rate comes in 150 psi.

  • Users report that this small unit is robust and efficient offering more of an “instant” hot water luxury to their daily living.
  • Save water by not waiting for “lag time,” running faucets until they get hot.
  • Easy install according to most who installed the systems on their own.
  • While not a “tankless” system, it still operates on the “on demand” premise.
  • Can’t be beaten for the price-point which allows buyers to purchase multiple units around the house.
  • Has been suitable for use in a mobile application such as Rv’s.
  • Poor reviews suggest the unit is prone to leaking.
  • Poor customer service has been reported by a number of buyers.
  • Complaints about the warranty not being fulfilled by the company.

The Specs

  • Dimensions – 17.5 W x 17.5 H x 14.5 D In
  • Install vertically or horizontally
  • Simple hard wired unit
  • Comes in 3-compact gallon sizes
  • 120-Volt plug-in connection

4. Takagi T-KJr2-IN-LP Indoor Tankless Water Heater

This Takagi tankless water heater is made to be used indoors in smaller spaces such as condos, apartments, and lofts. There is an outdoor option of this same unit that doesn’t have a venting system. The venting in this unit can be run either horizontal or vertical. A power cord is included with your purchase, making the electrical installation easier.

The unit has a remote control which can be used to make temperature adjustments that range from 99-degrees to 167-degrees. The digital display is easy to read and also gives feedback errors to make troubleshooting a breeze.


  • Users report this unit can run multiple water sources at one time with ease.
  • Easy install as a DIY project which keeps the cost of the project lower.
  • Users recommend using a water softener to help the system’s longevity
  • Contractors who have used this item have purchased units for clients due to good performance.


  • Users report having multiple ignition issues requiring hard to acquire repairs.
  • Reports of units failing between 6-months to a year.
  • Some buyers report that the heat exchanger is very fragile and needs more attention and care then is feasible.

The Specs

  • 19,500 to 140,000 BTUs
  • Bottom water connection with direct venting
  • 120-Volt unit
  • Weight 38-pounds
  • The unit has a freeze, overheating and power surge detection.
  • 6.6 Gallon per minute flow rating

5. Rinnai RUC98iP Ultra Series Propane Vent Tankless Water Heater

Similar to the natural gas unit mentioned above, this Rinnai option is the propane option for those who wish to use this alternative fuel source. The company states the flow rate of this system is 9.8 gallons per minute. The energy factor is set to 96% helping homeowners save on utility bills.

The compact space-saving size is a useful feature for those who need to optimize space and comes with an in-depth installation guide that can be done by yourself or with the help of a professional.


  • Users report high energy savings that are environmentally friendly.
  • It has two venting options as either a concentric or PVC venting system.
  • Easy installation as a DIY project for those who tend to be handier.
  • High flow output rating reported by users able to keep up with demand.


  • Customer service complaints with buyers unable to get the help they need for parts and service.
  • Customers with “HE” appliances say this unit isn’t compatible.
  • A few buyers reported the unit failed after a few months.

The Specs

  • Concentric or PVC venting options
  • NOx Ultra low emissions ratings
  • 199,000 max BTU’s
  • .96 Energy Factor
  • Dimensions – 10 x 18.5 x 26 inches
  • Weighs – 82 pounds

6. Rheem RTGH-95DVLN 9.5 GPM Twin Pipe Tankless Natural Gas Water Heater

Rheem spends a lot of time developing and testing their own products to meet the expectations of the tankless water heater industry. Their goal is always to exceed those expectations with a close eye on quality. In fact, the company uses third-party labs to test their products.

The system can be installed on your own with easy setup and installation guidance and service. The system has a digital display and built-in electric blower. This unit can be “daisy-chained” meaning two units can be connected to one another to act as one unit to serve larger homes and more people. The system works well for properties in higher altitudes up to 9,840 ft.


  • Two-pipe direct vent system designed for PVC pipe with easy installation.
  • Very low maintenance after installation is complete.
  • Worthy for cold weather climates that may struggle with other tankless systems.
  • Those who take a lot of baths report this unit can fill an 80-100 gallon tub with ease. The water temperature remains constant and doesn’t get cool.


  • Even with play by play instructions, self-install is reported to take hours
  • Some users report the company not honoring aspects of warranties.
  • Users report minor leaking that can lead to the unit not working.

The Specs

  • Digital display for temperature and maintenance codes.
  • Connect two together to serve larger applications.
  • 10-feet of thermostat wire included
  • 120-Volt power
  • Freeze protection from -30-degrees.
  • 9.5 Gallons per minute.
  • .94 Energy Factor
  • Dimensions – 18.5 x 9.8 x 27.5 in
  • Weighs – 82 pounds

Nice Things You Should Know Before Installing

Self-install – Installing a tankless water heater isn’t a “rocket science” project; however, it can be a frustrating one. After reading hundreds of reviews from users who decided to do a self-install of their tankless water heaters, most people say it could be done relatively quickly. Here are some things to consider if you choose to go this route for your system.

  • Read the manuals the whole way through before the unit even arrives at your home. When you have an idea of what you’re getting into before you’re sitting in front of the unit, baffled, you will be more clear about the tools you need and any additional parts required. This will save you the inevitable back and forth to a home improvement store and cut down on the overall installation time.
  • Read more reviews of the unit you decide to go with and ask people questions. When you can consult with others before your project begins, you might get some helpful tips and tricks before installing your particular system.
  • Be sure to check your warranty. Some companies will void your warranty if you install your system on your own.
  • Check your area to see if anyone can repair the type of system you plan to get. Tankless water heaters are not all the same and sometimes require specialty repair service contractors.
  • Look at the unit thoroughly before the delivery company leaves your home or business. Unpack it to check for damage since this is a more substantial investment and damage often happens during shipping.

Professional Install – Professional installations of tankless water heaters are sometimes a better fit for those who either don’t have the time to do it or may void their warranty if they try. Professionals who do this for a living can offer more than just installation help, they will also be able to give you more information about your system and perhaps become your go-to source for future maintenance and repairs. Here are some tips when considering hiring a professional installer for your tankless water heater.

  • Do your research and find out if the person/company works on your particular unit and not just “tankless systems” in general.
  • Ask the company you are purchasing from if they have a preferred vendor they use in your area, to install your system. This not only cuts down your research time in finding one but will help you ensure your warranty is safe and secure according to the company itself.
  • Look at online reviews to learn more about how long it takes to install your system. This will help you in two different ways. First, you will know how much time you’ll need to hire an installer and can better financially prepare for that time. Second, you’ll know if you’re being quoted the appropriate time by an installer to ensure you don’t get overcharged for labor.
  • Learn about anything extra you might need for your install. If you’re going to need additional equipment, make it a point to get that equipment beforehand so you’re not charged additionally for that by the person doing the work.
  • Ask your installer questions at the time of your appointment. This is the perfect opportunity to learn about how to best maintain your system, how to troubleshoot any issues you might have, and learn more about the unit in general.

Location of Install – Something that comes up regularly as a concern among tankless water heater users is where to install your tankless system. This might not seem like a big deal at first, so long as the unit is next to the incoming water and out of sight. But where you place your system is important in how it functions. The performance of the unit, as well as its efficiency, is impacted depending on where you decide to install your tankless water heater.

  • Easy Access – You want your tankless water heater to be easily accessible in order to make adjustments, maintain it or repair it if needed.
  • Use Existing Space from Old Unit – Sometimes, using the space that your old unit or tank-based system, makes for the perfect location since the plumbing is already done for you.
  • Refer to Your Owner’s Manual – Check the user manual for your new tankless system and see if there are any suggestions or requirements for where your unit is located.
  • Safety First – Consider the space you’re planning to install and be alert to too many electrical outlets, gas lines, shared plumbing lines, etc. so you are not potentially creating a fire or flooding situation.
  • Your Family – Make sure you install your unit away from roaming little ones who might be more curious than you can afford them to be.
  • Determine How to Vent the Unit – If your system requires a vent (most indoor gas units do), you’ll want to know what kind of venting is needed and plan for that.

Tips From Users Who Decided to go Tankless Heating

Some of the best advice comes from the people who actually use tankless water heaters. We thought it would be helpful to have a section dedicated to their suggestions and tips for installing and using a tankless system.

  • Understand your power needs with your new system, especially for those that are using an electric system. You’ll need additional room on your electrical panel, and that is helpful to know prior to your installation.
  • Consider your geographic location and how the groundwater temperature will impact your new tankless water heater. Some locations that see zero and below temperatures will likely want to go with a freeze-protected unit that is gas powered, rather than electric.
  • Some users say they don’t think the system is designed to pay for itself as an energy saver. While this can absolutely be a bonus with some tankless systems, the savings might not be seen for years and year to come. By that time, the unit may fail. So, think of this investment as more of a convenience value, which will help you be more happy with the unit overall.
  • Tankless water heaters are not “instant hot water” heaters. Just like tank-based systems, it can take a few minutes for hot water to reach your faucets. Don’t fall for marketing that promises this or you’ll be disappointed about your purchase. If you are seeking fast access to hot water, you should look into the point-of-use options such as the Bosch system mentioned above.
  • Stay current on maintenance of your system. Tankless water heaters do not require the same amount of maintenance a tank-based system does, but it’s still important to stay on top of it. This will help the system last longer and remain a safe, stable and reliable feature for your home.

Start saving much more with reduced circulation shower heads

If you are already utilizing or intend on using a tankless water heater, you can expect cost savings of as much as 60% percent on your water heating expenses. You can better increase those savings for roughly one more 50% by using water effective shower heads. By decreasing the flow from 2.5 GPM or probably an also higher GPM to 1.5 GPM or less, you’ll have the ability to conserve that much more.
You will find a variety of water efficient shower heads in our online store, as well as other water saving products designed to saver water as well as energy while maintaining a high level of performance. Remember, frail showers a thing of the past.

Consider using distillers ( filters )

A tankless hot water heater is particularly susceptible to tough water. When the water is heated, the calcium, as well as magnesium, will become scale much faster. Hot water aids in mineral material converting into a solid type. Tankless heaters and also storage-tank water heaters alike are very likely to come to be choked by range. Various other warm water-using devices, like dish washers, washing machines, as well as shower heads, are also prime targets for range build-up if left undefended.


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