The 8 Best Commercial Tankless Water Heater Reviews & Buying Guides

commercial tankless hot water heater

The commercial tankless water heater is a bit different from the residential tankless water heater in flow rate, water pressure requirement, and power, etc. Some of the commercial types can be cascaded up together to meet the massive demand for hot water.

Commercial tankless hot water heaters can be widely used for hotels and other public places for providing constant hot water. Here we offer you the best commercial tankless water heater reviews for you to choose the most suitable one.

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The 8 Best Commercial Tankless Water Heaters of 2020

How to Use Commercial Tankless Heaters

Commercial tankless heaters are different from other heaters in terms of power and flow rate. They are designed to meet the rising water demand in the commercial space. After installation, you are now set to use. It heats water as it flows through it depending on the customized water temperature. You can view and operate it using the control button and the temperature will be displayed on the screen. So when water flows through this unit it is heated continuously. The user will enjoy the hot water and once he is done the unit shuts off automatically as a safety precaution measure and go save on energy.

Why Go with the Tankless Water Heater for Commercial Purposes

The tankless water heater is the best option when it comes to commercial purposes. It is cost-efficient because you will heat water only when it is needed. There is a likelihood that you will pay less on bills compared to other conventional water heaters. Additionally, it also keeps up with the demand. After all, even if you have a larger tank you need to know that it will run out eventually. Therefore, with the tankless water heater, the water will never run out because it can keep up with the increasing demand depending on the water usage. A tankless water heater for a commercial purpose is considered a green technology because it is eco-friendly and energy-efficient. You can enjoy the ultimate supply of hot water because they require less maintenance and they are energy efficient.

Best Commercial Tankless Water Heaters Reviews

1. Rinnai RUC98iN Ultra Series Tankless Water Heater

best commercial electric tankless water heater
best commercial tankless water heater





  • High-temperature range

For commercial use, the temperature can go up to 185 degrees F, perfectly meets the demand of constantly large flow hot water supply. But you need to get an extra commercial remote controller. Even for residential use, the maximum temperature reaches 140 degrees F.

  • Large flow rate

The flow rate of this unit reaches 9.8 gallons per minute; the high flow rate enables providing endless hot water for you. The power requirement ranges from 15200 to 199000 BTU per hour. But it needs only two watts to keep the machine up and working.

  • Short waiting time

It takes about 20 seconds for the water to heat up, and once it warms up, you will have unlimited hot water. The working noise of it can hardly be heard. It offers two venting options, concentric PVC and twin-pipe for durable choice.


  1. Two venting options
  2. 0.95 high energy rating
  3. High-temperature range with commercial remote
  4. Five-year warranty on heating parts
  5. No noticeable noise
  6. Needs only 2 watt to keep machine up and running


Need to be installed by professional

2. Rinnai RL75iN Natural Gas Tankless Water Heater

commercial electric tankless water heater
commercial tankless water heater





  • 160 degrees F temperature

The maximum temperature for commercial use reaches up to 160 degrees F; of course, you also need to buy the remote controller separately. The residential temperature range is between 98 to 140 degrees F.

  • 7.5 GPM flow rate

The maximum water output for this unit is 7.5 gallons per minute at 120 degrees F; power consumption is between 10300 and 180000 BTU per hour. One machine is able to support two or three fixtures a time. If you intend to use it for industrial, you need to cascade several of them together.

  • Easy operating control panel

Temperature and error codes on the screen, you can adjust the exact water temperature you want with easily operated buttons. Electronic solenoid valves are equipped to control water flow and gas.


  1. 82% thermal efficiency
  2. Outdoor air for safe combustion
  3. Quiet working performance
  4. Perform flawlessly
  5. Self modulate technology to heat water only when you use it
  6. Energy efficient


  1. It fluctuates a bit
  2. Venting kits can be hard to install

3. Rinnai RL75eN Natural Gas Tankless Water Heater

commercial tankless water heater reviews
commercial tankless hot water heater





  • Large temperature range

Like the RL75iN series, the industrial temperature range of this unit is between 98 and 160 degrees F, and the remote controller needs to be bought separately. There is also a control unit that comes with the machine, but you need to hook it up if you want to adjust the temperature with it.

  • Endless hot water supply

The maximum flow rate of this type is 7.5 gallons per minute; water temperature always stays constant, even multiple bathrooms or faucets are using the same time. But the waiting time is quite long.

  • Freeze protection

The machine is equipped with freeze protection devices; once the outdoor temperature reaches low, the smart unit senses the cold weather and automatically takes measures to protect itself. It is also Wi-Fi capable, anywhere you connect the internet, you can control the machine up remotely.


  1. Easy to install
  2. Stable water flow and temperature
  3. 82% thermal efficiency
  4. Wi-Fi enabled remote control
  5. Easy operating control panel
  6. Constantly hot water supply


Working noise is a bit loud

4. Rheem RTG-64XLN Tankless Water Heater

best commercial tankless water heater
commercial tankless water heater





  • Easy connection

When you use it as a commercial-grade tankless water heater, you can connect several of it, and the connection process is quite easy. Besides, it is both high and low altitude capable.

  • Energy efficient

Heat exchangers are made by copper, 82% thermal efficiency gives you more energy. The power range of it is from 11000 to 150000 BTU per hour. It is said that the unit is able to save 1100 gallons of water each year for you. The low NOx design makes it more environmentally friendly.

  • Digital control

Digital console displays the temperature and error codes, and also maintenance code shows on for reminding. There is no cold sandwich effect with hot starting program; the machine goes on working for a few minutes after it shuts off.


  1. Easy to use
  2. High and low altitude available both
  3. Energy-efficient and heating cost saver
  4. Exclusive water-saving settings
  5. No cold water sandwich
  6. Suit a good range of power input


Need to be installed by professionals

5. Stiebel Eltron Tempra Plus 24 kW Tankless Water Heater

best commercial tankless gas water heater
best commercial electric tankless water heater





  • Stable water temperature

The advanced flow control system is used to control constant water temperature in different flow level when used industrially, you will need it to keep stable and flawlessly hot water flow by regulating water pressure automatically.

  • Full power modulation

This tankless water heater is equipped with a full power modulation system, capable of meeting the demand for large power use for commercial. It has the power to provide about 5 gallons of water per minute. And it shows the best performance where supplied water is under 45 degrees F.

  • 99% energy efficient

The thermal efficiency of this unit reaches as high as 99%; thus seldom energy is wasted in using. It is frequently used for commercial because of its high-level electronic parts and a reliable cover. The working noise is low, barely be heard in working.


  1. No mechanical switches
  2. High quality
  3. Compact design
  4. Self-modulating technology to save heating costs
  5. Supports full power modulation
  6. The most technologically advanced electric water heater


Difficult to install, needs 240v power and heavy-duty wiring

6. Takagi T-K4-IN-NG Tankless Water Heater

industrial tankless water heater
best commercial tankless gas water heater





  • Self-diagnostic system

It is equipped with a self-diagnostic system and led light shows off on the console; error codes also show when something wrong happens. Besides, the freeze protection system is installed to prevent the machine from getting frozen.

  • Free installation

The heating machine can be both installed for indoor and outdoor, but it needs to get venting facilities for indoor installation. You are free to install it either vertically or horizontally. If you lack basic knowledge on it, just find someone professional to help you with installing.

  • Stable water temperature

Water temperature is not affected by the climate and can always keep stable. Temperature ranges from 99 degrees F to 167 degrees F with remote control for commercial use. The power required ranges from 11000 to 190000 BTU per hour.


  1. Both indoor and outdoor installation
  2. Digital remote control
  3. Maximum flow rate reaches up to 8gpm
  4. An internal freeze protection system
  5. Hot water output is not affected by climate
  6. Large power


Installing remote control is an extra cost

7. Naiven NPE-240-A Tankless Gas Water Heater

industrial tankless water heater
commercial tankless hot water heater





  • Ready-Link cascading technology

The ready-link cascading technology enables you to cascade up to 16 units, and it supports common vent up to 8 units. The maximum flow rate of this unit is around 9 gallons per minute; thus, when you cascade them up, you will be able to use it for commercial use easily.

  • Recirculation pump built-in

This machine is regarded as the most technologically advanced tankless water heater, it has built-in hot buffer tank and recirculation pump, in order to eliminate cold water sandwich and save water bills by shortening the waiting time for hot water, it also reduces the money on buying an extra pump.

  • Stable temperature

The machine will always keep the water temperature stable; it quickly corrects temperature if it draws stop suddenly. The external interface shows temperature and error codes so you can easily adjust the temperature you want.


  1. Satisfying customer service
  2. Powerful enough for commercial use
  3. Clear installation and using instructions
  4. Condensing types of saving energy
  5. Fast heating time and short waiting time
  6. Intelligent preheating system


  1. Slightly working noise can be heard
  2. Do not come with a remote, you need to buy separately

8. Noritz NC380-SV-ASME NG ASME Tankless Natural Gas Water Heater

commercial tankless water heater
industrial tankless water heater





  • Large flow rate

This unit is designed as a commercial tankless water heater used in hotel maximum flow rate reaches as high as 13 gallons per minute, perfectly meet the demand of a large volume of water.

  • Brilliant quality level

The heat exchanger is made by commercial-grade copper; it is highly corrosion resistance and heat resistance. It is compatible with circulation units; you can also install a circulation pump inside to shorten the waiting time for hot water.

  • High energy efficient

This unit is both natural gas and propane available, for propane, thermal efficiency reaches 84%, while natural gas efficiency is 80%. The temperature range of the unit is between 100 and 140 degrees F.


  1. Designed for hotel
  2. High temperature
  3. Highly energy efficiency
  4. Compatible with circulation units
  5. Excellent material on heat exchanger
  6. Both natural gas and propane available


Need to be installed by professional

Can Tankless Water Heaters Work in Commercial Applications?

Tankless water heaters have proven to be the best option in commercial and residential applications. They are good in cost reductions, energy savings, and efficiency. They produce hot water upon demand which makes it an incredible option and extremely efficient. When it comes to commercial applications it is important to consider a tankless water heater that is sized properly to ensure it can meet the demands. Additionally, the flow rate is also important based on the demand for hot water supply. Therefore, most commercial spaces use tankless water heaters because they are the best and effective.

Is Water Quality Important when It Comes to Commercial Application

Water quality is essential in commercial applications. As much as you want to have a local water supply to save on cost, it is equally important that the water contains essential minerals such as manganese, magnesium, and calcium because the tankless water heaters require quality water compared to its counterpart.

Therefore, you need to ensure that the water being supplied meets the water quality standards. Some manufacturers have given specifications on the type of water that should be heated using the tankless water heater.

Benefits and Limitation of Gas Commercial Tankless Water Heater

There have been lots of discussions on which one is better between electric and gas heaters. So let’s get some insights about the benefits and the limitation of the commercial gas heater.


  • Gas water heaters are easy to install.

This makes it convenient because of the clear instructions manual and you are not required to have lots of technical skills. Once the commercial space has a gas supply them it makes it easy to connect it to the gas supply and install it in its designated location.

  • They are also cheaper compared to their counterpart’s electric tankless heaters.

When you compare the cost of energy consumed by the electric you will prefer the gas heaters. However, propane might be expensive than natural gas but it is still cheaper than electricity.

  • They are good at recovery after heating large amounts of water.

The gas supply will be replenished quickly after the heating process is complete.


  • Rerouting of gas lines

This can occur especially because the location of the gas heater might be far from the main gas supply. Therefore, the contractor might be forced to reroute the gas line which leads to additional costs.

Features of Commercial Tankless Water Heater

Commercial tankless water heaters are one of the best when it comes to commercial applications. This is because they can heat large amounts of water to accommodate the rising demand. Most of them help in saving Time, electricity, space and they are also safe and convenient.

  • Time saver

Tankless water heater types save much time for you, no waiting time for hot water, and you can always use hot water instantly.

  • Electricity saver

There is no need to wait for preheating and warming of water, no heating loss in the whole using process.

  • Space saver

Unlike a tank water heater, it is designed to compact and small, suitable to be installed anywhere you want. Even for a small studio, you can also install a large flow commercial type.

  • Safe

Most of the large power tankless water heaters are designed with overheating protection and overpressure protection system to protect the machine in danger.

  • Convenient

It is installed directly in the bathroom; there is no need to break the wall; multiple buttons are set to adjust the water temperature.

How to Choose Commercial Tankless Water Heater?

Tankless water heaters have been popular among several countries in Europe and other parts of the world for decades. However, consumers in North America, particularly the United States of America, have turned to its benefit in recent decades. Since then, tankless water heaters have become highly popular, resulting in several models and designs being featured in today’s market. This makes it relatively challenging when it comes to choosing the right one; as a result, we have design guides of best tankless water heaters to help you choose the right one.

The industrial tankless water heater is normally used for hotel, a large volume of hot water is demanded, and you need to get several cascaded up together. On choosing a commercial tankless hot water heater, there are some tips:

1. Quality

The quality level of a commercial tankless hot water heater determines its service life and using safety. There is a specific standard on heating exchanger and other internal materials. Choosing a high-quality one can save a large amount of money in maintenance and repair.

2. Flow rate

The flow rate of a commercial tankless water heater needs to be large enough, or it is unable to provide a satisfying showering experience. The average flow rate of each is around 9 gallons per minute; of course, you can also cascade several small flow rate one based on your actual needs.

3. Power

The power of the heating machine determines water flow; if not powerful enough, hot water can not flow flawlessly. Therefore, choosing a powerful one can do you great help.

4. Energy efficient

As the power rate of commercial units is quite large, they are actually pretty costly in using period; if they are designed high energy efficiency, they will help save much money for you each month.

5. Temperature

Because of its special applications, commercial tankless water heater temperature range is normally higher than residential type. It ranges from 98 degrees F to 185 degrees F, while maximum temperature reaches up to 140 degrees F.

commercial tankless water heater
best commercial tankless water heater

Commercial Tankless Water Heater Prices

Every family needs some water heater, especially for large families residing in cold places. Whether you have a small family or a large one, it is relevant that you get some way of supplying hot water for your family. For family use, just a small capacity tankless water heater can be appropriate. However, for commercial purposes, you might have to go for a high capacity tankless water heater.

Are you planning to supply hot water for your commercial purposes? If you are planning to run a high-class hotel or you already have one, a smart tankless water heater can serve you a great deal. It is an excellent idea to desire to know the cost, but this should come after finding out whether or not this option will serve your needs.

The heater price

The cost for commercial tankless water heater can be categorized into three groups. The first cost is that of buying the heater itself. It ranges between $100 to $2,200 for the gas generated heaters and $100 to $800 for a gas generated heater. This is merely the cost of buying the heater and nothing else. Some companies might offer you free delivery.

Installation costs

The second category is the heater installation cost. This ranges from $150 to $700 for the commercial electrical heater and $600 to $1,500 for a gas water heater. This cost comes immediately after the cost of buying.

Operation costs

Once you have installed it, then comes the cost of operation, which is majorly contributed to by the cost of the energy you use. This cost is relatively different for most people based on how much they spend. On overage, the price goes between $75 to $300 per month, depending on the number of guests that you serve. The same amount can serve almost a whole year when it comes to whole-house electric tankless water heaters.

When considering the cost of a commercial tankless water heater, you have to consider the two options. This is the best way of preparing psychologically for you will have to spend.

Is It Hard to Maintain Commercial Water Heaters

Most commercial sectors are opting for commercial tankless heaters because they are very effective. They can supplement the rising demand and they are cost-effective. However, it is very expensive to maintain compared to tank heaters. The good thing when it comes to maintenance is that it requires to ber descaled twice in a year. This saves expenses bit you will also have to do some frequent inspections to ensure it operates effectively and safely. They are relatively efficient when it comes to energy but you will spend a lot of money on maintenance.

Maintenance of Commercial Tankless Water Heater

Maintaining your tankless water heater will help last for an extended period. To do so, you will have to do the following;

· Wipe the cover

This will take you approximately 10 minutes. You should clean the outside surface of your unit using a cloth along with a nonabrasive cleaner. This will aid in preventing rust from occurring.

· Pipe inspection

During winter or cold seasons, you should consider inspecting the pipe installation more frequently and assess any splits or cracks available. The primary function of the insulator is to protect the pipe from freezing, letting a small amount of water to go through it is essential whenever the weather is below freezing.

· Assess pressure valves

You will have to open the pressure relief valve and close it to ensure that it is operating accordingly. Run the lever and allow water to flow out to the ground and then ensure that the water is shut off when closed. Take precautions when carrying this out since the water is boiling.

· Clean air filter

Units that feature air filters should be cleaned frequently; this will depend on the surrounding of your living area.

Can A Commercial Tankless Water Heater Be Installed For Home Usage?


You can use a commercial tankless water heater in your home; however, several vital aspects need to be met first. Initially, a tankless water heater was designed for residential use; however, it grew in popularity in various commercial applications.

When compared to tank water heaters, tankless water heater occupies a significantly small amount of space, making it ideal for use not only at home but also dormitories in universities, colleges as well as several military applications.

Is It Necessary To Install A Water Softener For A Commercial Tankless Unit?

A water softener is highly essential for a commercial tankless unit since they aid in preventing scales from developing. In addition to that, water softener assists in ensuring that your water has zero hardness. You ensure that your water softener is correctly installed for it to work accordingly.

Once installed correctly, the water softener will limit the effect of scaling, which is a common problem. You might as well consider purchasing a water softener that features an up-flow brining as well as a proportional brining; this will ensure that the hardness level regulated accordingly.

Best Water Softener For Tankless Water HeatersWhirlpool WHES30E 30,000 Grain Softener

choosing water softner


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What Applications Are Best Suited for Commercial Tankless Water Heater

Commercial water heaters are designed to meet the high demand for hot water in commercial places. They can heat large volumes of water which are used in washrooms, dishwashers, whirlpools, kitchens, and any other critical point that hot water is needed. They are also suitable for places such as restaurants, fitness centers, hospitals, offices, and apartments. Therefore it is important to purchase quality commercial tankless water heater to ensure that it can serve for long.

Do Commercial Tankless Water Heaters Pose Any Safety Issues?

Tankless water heaters are very sensitive when it comes to safety. This is because improper installation of the tankless water heater can be fatal since water can be heated to a temperature of 140°c within 5 seconds which is the potential of causing third-degree burns. This can bring devastating effects when the problem is not noticed as early as possible.

When a system operates on gas, it requires some caution, and a tankless water heater is no exception. Since most of the tankless water heater serves using natural gas, they feature the same concern just like any other gas-powered system out there.

For those powered using electricity, then it is potentially hazardous like any other electrical appliances. Any malfunction can cause a faulty electrical circuit which can lead to fire accidents and damage to other appliances.

Therefore, it is always important to take safety precautions and ensuring the unit is installed by a professional. It should also be inspected periodically to ensure it is functioning optimally. Otherwise, when it is properly managed tankless water heaters have a longer lifespan; they are safer and have a lower risk of water leakages.

When compared to a storage tank, tankless water heaters are safe despite carbon monoxide concerns it possesses. Since there is no storage tank around, a tankless water heater is very safe in places with children around. If you have a child and you are concern about their safety, then you should consider installing a tankless water heater over a storage-tank water heater.

Is It Effortless To Install A Commercial Tankless Water Heater?

This will depend on various aspects, including the brand and type of the tankless water heater you have. In addition to that, clarity of the manufacturer’s process of installation, as well as the existing venting design available in your home, will determine how difficult or easy it will be to install your tankless water heater.

However, most tankless water heater designs available in today’s market come with an installation manual that is easy to understand. This makes the entire process relatively easy. You should, however, keep safety in mind when performing this process.

Can One Tankless Water Heater Work In A Large Hotel Or Hospital?

An electrical tankless water heater system was designed for point of use applications such as hand washing. This makes it not less viable for use in large hotels or hospitals. On the other hand, a gas tankless water heater can be ideal for commercial usage; however, you will require more than one gas tankless water heater system to meet the needs of a large hotel or a hospital.

Which Are The Critical Areas Of High Water Consumption In A Hotel?

Critical places are those places that require a constant supply of water to meet the demands. Hotels are some of the common places that you will find a tankless water heater. This is because there is a high demand for hot water in such a commercial space. Here are some areas that experience high water consumption in the hotel.


This requires more water when sprinkling flowers and other plants to make the garden green and presentable.


Water is required when cleaning utensils and other cutlery that will be used in the hotel. Depending on the traffic and the demand then there will be high water consumption in such an area.

-Swimming pools

This is yet another area that requires constant water supply.

-Laundry and bathroom

Both are essential spaces in a hotel which also consumes lots of water.

Are Commercial Tankless Water Heaters Expensive To Take Care Of?

Maintaining commercial tankless water heaters are relatively expensive. Since business prefers operating on water heaters that need few maintenance services, tankless water heater becomes more preferable. This is because they require descaling only twice a year; however, support is not relatively affordable. Despite the fact that they require less descaling, tankless water heaters need a frequent visual inspection to assess its operation. When compared to its low energy spending ability, tankless water heaters are relatively affordable but a bit expensive when maintaining it.

Our Verdict:

When compared to storage tank water heaters, tankless water heaters are not only safe by also easy to maintain and are very long-lasting. Therefore, choosing a tankless water heater over a storage-tank water heater is highly recommended.


Because of the great demand for hot water and power, one commercial tankless water heater is normally not powerful enough to meet the need in large hotels or hospitals. Therefore, you need to cascade several of them together. If you lack enough knowledge of it, please ask the manufacturer first and then get a professional to help you.

What We Pick Is…

We would like to suggest Rinnai RUC98iN Ultra Series Tankless Water Heater for you; the maximum temperature for commercial use is up to 185 degrees F, thus is able to provide flawlessly hot water for you.

It has a large flow rate and 0.95 high thermal efficiencies; the powerful performance makes it the perfect one for commercial use. Heating time is quite fast and helps save much water and heating costs.
If you have an interest in the item, please feel free to get more information and price details on Amazon, there will always be a large discount on Amazon to save a large sum of money for you.

commercial electric tankless water heater
commercial tankless water heater reviews



David: Penn State-educated Mechanical Engineer and Business-savvy Fluid Dynamics Specialist. Balances family plumbing business support with a thriving engineering career at a top, undisclosed company. (they want it that way) I help Will with plumbing and HVAC needs on his Real Estate.

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