Commercial Tankless Water Heaters

Best Commercial Tankless Water Heaters for Business, Restaurant, Hotel

Unlike residential applications, commercial projects don’t have a one-size-fits-all solution. Besides, the water-heating technologies are many and various, which is why engineers have myriads of options.

Can tankless water heaters work in commercial applications?

Even if tankless technology was developed for residential purposes, it has slowly started to become popular in commercial applications as well.

The first thing to decide is whether the hotel/restaurant/business is going to use gas or electric power. The electrical tankless system was developed mostly for point-of-use applications (hand washing is one). Therefore, it’s natural that the electric tankless water heaters don’t make a viable option for commercial projects.

It may take more than one gas tankless water heater for meeting the needs of a commercial application, especially if it’s a large one. When using more than one unit, there’s built-in redundancy. Therefore, if one unit fails, the business/hotel/restaurant is going to keep on working until the unit is serviced.

The commercial tankless water heaters are commonly used in hotel, where there’s a high demand for hot water.

Why go with tankless water heaters for commercial purposes?

Tankless water heaters bring a lot of benefits for any type of use, commercial or not. Here are the most significant to mention:

  • It saves electricity

When using a tankless water heater, you and your clients don’t need to wait for the water to preheat and warm. There’s no more heating lost throughout the process either.

  • It cuts down the time

Hot water comes on-demand, so you no longer wait for hot water, and you use it instantly.

  • It saves space

Unlike the traditional water heating systems with tanks, the tankless water heaters are small and compact, allowing installation in tight spaces. You can use a large flow commercial unit even for a small studio.

Are there any things to consider when selecting the commercial tankless water heater?

Due to the numerous and various options, it makes perfect sense that some aspects should be accounted for when selecting. Here are the most important ones:

  • Flow rate

The flow rate has to be large so that it ensures a pleasant showering experience. 9gallons per minute is the average flow rate, but a small flow rate can work in some situations as well.

  • Quality

The quality of the commercial tankless water heater gives you the durability and service life. You want to spend for the long run, so look for high-quality models.

  • Power

The power impacts the water flow, and when it’s low, the hot water isn’t going to run right. Look for units with high energy for commercial applications.

  • Temperature

Because of specific applications, commercial tankless water heater temperature is higher than in the residential models. 98 to 185F degrees is the typical range, with the heat getting as high as 140F degrees.

  • Energy efficient

The commercial units are large, which means that they use a lot of power. However, good models are supposed to be energy effective, which can only cut down the monthly spending.

One last suggestion

There are numerous and various commercial options that can successfully work for a hotel, business, or restaurant. Pay attention to the details and always be willing to spend an extra buck. It’s going to be a wise investment in the long run.

Top 10 Best Commercial Tankless Water Heaters for Business, restaurant, and hotel

   1. Rinnai RL Series HE+Tankless Hot Water Heater

The Rinnai RL Series HE+ Tankless Hot Water Heater: Outdoor Installation is both an affordable and dependable option for commercial applications. However, the unit brings more than good value for the money, and you shouldn’t skip it from your shopping list.

It’s a high-efficiency water heater that uses natural gas, and it’s designed exclusively for outdoor installation. It can provide up to 7.5GPM hot water flow rate, which is a good number for various commercial applications.

Thanks to the circ-technology, you may set the re-circulation patterns that match the everyday needs. The unit allows Wi-Fi monitoring, easing out the operation. It’s not difficult to install and has ample capacity. It comes with insulation valves, and you can make adjustments to use it with propane as well.

Operating the unit is straightforward, and you can adjust the temperature according to your needs at the moment.

The heat exchanger comes with 120months residential factory warranty, whereas the parts have 60months warranty.

Here’s the list of pros:

  • It’s made with re-circulation technology
  • It allows Wi-Fi monitoring
  • It’s large capacity and reliable
  • It ensures 7.5GPM hot water flow rate

The shortcomings aren’t significant:

  • The installation of the gas line can get pricey
  • The fix for the CVPC pipes is a bit tight

Regardless of the minor issues, the unit is a solid choice for some commercial applications, especially considering the buck you’re paying.

   2. Noritz Indoor Condensing Direct Tankless Hot Water Heater

For the indoor installation, the Noritz NRC66DVNG Indoor Condensing Direct Tankless Hot Water Heater is a solid choice, especially since it’s a condensing model.

The tankless water gives endless hot water, and you can even schedule its operation according to your needs. PP, PVC and CPVS pipes and fitting work for installation, which should go smoothly for anyone with handy-man skills.

The high efficiency of the unit recommends it for commercial use. It comes with 6′ power cord and remote thermostat for easy use. The advanced heat exchanger and built-in controller ensure its reliable performance for a reasonable amount of time.

The flow rate is around 6.5 GMP, and you can use the water heater for more than one shower at the same time.

We should also mention the versatility of the model which allows different venting options thanks to its design. You can use it with various terminations and adapters.

It’s a small unit that doesn’t need much space and operates quietly too. The instruction is user-friendly, and the group is a safe and reliable choice.

Let’s have another look at the positive aspects:

  • It’s dependable and safe for commercial applications
  • It’s small and runs silently
  • It allows versatile venting
  • You can use it for several showers at the same time

Don’t let the minor downsides change your mind:

  • It doesn’t heat the water instantly
  • Should anything go wrong with it, not many plumbers are going to be willing to fix it

All in all, the unit is dependable, versatile, and can serve more than one shower at a time. It comes for an attractive price, which can seal the deal for many.

   3. Takagi Condensing Indoor Tankless Water Heater

Many professionals are going to swear by Japanese manufacturers when it comes to the tankless water heater. The Takagi T-H3-DV-N Condensing Indoor Tankless Water Heater doesn’t make an exception, and it’s a fantastic option for many commercial projects.

The water heater provides endless hot water, and it doesn’t need much time to heat the water. Its compact shape allows easy installation, whereas the medium size lets you save storage space.

You don’t need to worry about any pilot light, and the unit comes with computerized safety features. It has an Ultra-Low NOx emission grade, and it’s powerful. It may provide hot water for four bathrooms in warmer areas or three baths in colder regions with just 199,000BTU gas input. The 10GPM flow rate recommends it for commercial projects.

The noise level is 55dB which means that the unit runs quietly. You can use it with PVC piping, with many appreciating the installation to be effortless.

The unit has a solid build, and durability feels to it. It’s an indoor condensing unit so you shouldn’t worry about energy efficiency.

We’ve shortened the pros to the following:

  • It’s durable and has 10GPM flow rate
  • It runs quietly and has a compact profile
  • It handles several showers at the same time
  • It comes with computerized features and no pilot light

The cons shouldn’t scare you off:

  • You need proper draining since it’s a condensing unit
  • It’s quite sensitive to the scale buildup, so use water softeners for hard water

Even if the group isn’t all roses and rainbows, it’s still a dependable, powerful, and energy-efficient model that works for hotels and restaurants too.

   4. Rheem Prestige Natural Gas Outdoor Tankless

The Rheem RTGH-95XLN Prestige Natural Gas Outdoor Tankless 9.5 GPM has an impressive .94Energy Factor (EF), which is why it works in various commercial applications.

The unit features a stainless steel condensing heat exchanger that sustains an excellent performance for a long time. It also comes with a two-pipe direct vents system which is designed for PVC pipe, for more versatility.

The minimum flow rate that the unit can handle is .26GPM, whereas the minimum activation flow rate is .40GPM. The digital remote control and 10-ft thermostat wire allow effortless installation and operation.

In case of high demand applications, the EZ-Link cable lets you connect two units, while they operate as one. You can connect up to six units thanks to the optional MIC-6 manifold control board. Should you go with 20 water heaters, the optional MIC-180p plus and the MICS-180 manifold control are available.

The unit also has the high-altitude ability, up to 9,840ft elevation. The compact profile saves storage space, whereas the intelligent electronic controls increase the energy efficiency and safety. The unit comes with digital display for maintenance codes and temperatures setting, self-diagnostic system, and built-in electric blower.

It’s an environmentally friendly unit with Low NOx burner and freeze protection to -30F degrees.

Here’s our take on the pros:

  • It comes with capable stainless steel condensing heat exchanger
  • You may connect several units, according to the demands of the commercial scenario
  • It features a digital display, self-diagnostic system, and built-in electric blower
  • It has freeze protection and Low NOx burner

The inherent flaws shouldn’t stress you out:

  • It’s a large unit, even if the profile is compact
  • It’s not the quietest option

For the many features, design, and performance, the water heater is a wise investment for high demand applications any time.

   5. Takagi Indoor Tankless Water Heater

Made for indoor installation, the Takagi T-K4-IN-NG Indoor Tankless Water Heater is impressive within the built, performance, and features. It allows direct-vent conversion, while it needs 11,000 to 190,000BTU/hr for an excellent performance.

The unit has an 0.82 energy factor and gives 8.00GPM maximum flow rate. The design is smart, and the unit comes with water temperature safety control and exhaust. It’s environmentally friendly and cuts down the gas bills by 45%. It can serve two and even three bathrooms at a time. Due to its size and power, it can help apartments with 2-3 baths and mid-size residential homes.

It’s a strong, yet lightweight unit that has an ultra-compact design so that you can mount it on the wall. The remote control eases out the operation, and the group runs quietly. It gives impressive output, and it’s excellent value for the price.

Here’s what we like the most about it:

  • It has an 0.82 energy factor
  • It’s environmentally friendly and dependable
  • It has a compact profile and allows wall mount
  • It’s powerful and silent

The negative aspects are nothing to worry about:

  • You have to have basic plumbing knowledge to install
  • The water needs some time to travel

With so many functional elements to focus on and only some minor issues to consider, the unit makes a reliable buy nine times out of ten.

   6. Rinnai RUC98iN Ultra Heater

The 0.96 energy factor of the Rinnai RUC98iN Ultra heater is the selling point. However, the water heater comes with several functional aspects.

The water heater allows concentric or PVC venting, whereas the profile saves the storage space. The unit also has Ultra-Low NOx emissions, and its rate input ranges from 15,200 to maximum 199,000 BTU.

It’s a condensing tankless water heater that is 95% thermal efficient on natural gas and propane. The residential temperature ranges from 98 to 140F degrees, whereas the temperature for commercial applications goes from 98 to 185F degrees.

The unit uses electronic ignition and is compatible with Full Line of Rinnai Digital Controllers. It comes with isolation valve and two pressure relief valve. The control for temperature is accurate, and the unit allows re-circulation the system.

Installation may be easy for some, despite the several walks to the hardware. The manual is easy to follow, and the unit runs quietly. The customer service is excellent, and the water heater is highly dependable. It comes with a limited 5-year warranty for the heat exchanger, 5-year for the parts, and one-year o labor- for the commercial use.

We should list our favs:

  • It allows concentric or PVC venting option
  • It has an 0.96Energy factor
  • It comes with isolation and pressure relief valves
  • The customer service is great

The downsides shouldn’t stress you out:

  • There is a short delay for the hot water
  • Some did report troubleshooting sooner than expected

No matter the inherent flaws, rest assured that a unit is a dependable option for commercial use anytime.

   7. Rheem Indoor Direct Vent Tankless Natural Gas Water Heater

The Rheem RTG-95DVLN 9.5 GPM Indoor Direct Vent Tankless Natural Gas Water Heater is quite the power horse within the category. The unit ticks most boxes for the commercial tankless water heater.

The stainless-steel condensing heat exchanger is excellent, and the unit has a 94% energy efficiency. It presents smart electronic controls which improve both the safety and the energy efficiency.

It’s a self-diagnostic system which makes both the installation and service effortless, with digital display for showing temperature setting and maintenance codes. The unit comes with two-pipe direct vent system made especially for PVC pipe, and built-in electric blower for more straightforward and safe use.

Thanks to the EZ-Link cable, the unit is reliable in high demand applications as you can link two or more water heaters and operate as one. You can install Manifold for six units or up to 20 units with the optional MIC-185 and the MICS-180 manifold control assembly.

The design and build of the unit make it safe to use up to 9,840ft elevation above sea level. The unit comes with digital remote control and 10ft. of thermostat wire. The freeze protection to -30F degrees sustains the performance of the water heater.

The temperature is consistent, and the low flow rate turns on add on the list of positive aspects. The manufacturer and customer service are more than happy to help, when in need.

Here’s what we like about it:

  • It’s a condensing indoor unit with 94% energy efficiency
  • It allows the connection of several water heaters
  • It includes several safety features
  • It has freeze protection and high-altitude ability

The inherent problems aren’t significant at all:

  • It’s a tad noisy
  • Installation isn’t that easy

Hands down for Rheem for manufacturing another reliable, secure, safe to use, and dependable indoor condensing water heater that works in high demand applications too.

   8. Noritz Residential Condensing Outdoor

A medium-sized restaurant should be more than satisfied with the Noritz NRC111ODNG Residential Condensing Outdoor.

The unit is quite representative of the modern high-efficiency water heating. It’s made with commercial-grade K-Copper which is 25% thicker than another type of copper.

The flow rate is as high as 11GPM, which makes the unit stand out from the crowd. The water heater is Quick Connect compatible, so you may easily connect two identical units for better redundancy and increased capacity.

The unit comes with a controller, which eases out the operation. You need a valve kit for proper install, so make sure you buy it too.

Despite its power, the unit is small and lightweight. It uses as much as 199,000BTU, which is satisfying for a restaurant. It cuts down the bill with 50% and comes with an impressive warranty too.

Here’s our take on the pros:

  • The heat exchanger is made with commercial-grade K-Copper
  • The flow rate is 11GPM, and the unit is durable
  • It comes with a controller
  • It’s Quick-Connect compatible

We’re not backing down over some minor issues:

  • The risk for some pressure drop isn’t null
  • The water needs a couple of seconds to run through the system

Be that as it may, the unit is a dependable, durable, and sturdy option to install for a restaurant.

   9. Rinnai Ultra Series Condensing Indoor Natural Gas Tankless Water Heater

The Rinnai RUR98iN Ultra Series Condensing Indoor Natural Gas Tankless Water Heater is part of the high-end category of the commercial tankless water heater. Therefore, scroll down for the details to find out why.

The condensing technology features dual heat exchangers that offer impressive efficiency, with the unit having a .96 Energy Factor. It’s also Wi-Fi capable.

The water heater comes with a built-in circulation pump and internal by-pass pipe for internal “re-circulation). The re-circulation feature lets you have hot water for as long as you need it. It also includes isolation valves and thermal by-pass valve, for safer and more effective performance. The MCT 195T remote controller allows you operation from a distance.

The indoor water heater is Rack System compatible, and it’s safe to connect to ½” gas line. The unit provides both PVC and Concentric venting, for increased versatility. The flow rate at 50F degrees is reasonable.

It’s a small unit that needs minimum space while offering maximum output. It requires 60-70% less space than a 50-gallon tank. It only needs a couple of seconds to heat the water and runs quiet too.

Let’s have a second look at the functional aspects:

  • It comes with a built-in circulation pump and internal by-pass pipe
  • It provides both PVC and concentric venting
  • It needs less space, and the output is impressive
  • It heats up in a couple of seconds, and it’s dependable

The minor problems don’t undermine the overall value in any way:

  • It can get noisy when circulating the water
  • Installation isn’t for everyone

The unit is the jack of all trades with all the features, build, and body and its nitpicks don’t alter its value in any way.

   10. Takagi ASMENG Heavy-Duty Natural Gas Tankless Water Heater

With a maximum gas input of 380,000 BTU, the Takagi T-M50 ASMENG Heavy-Duty ASME Certified Commercial Natural Gas Tankless Water Heater is one of the best options for a restaurant or hotel.


The entirely modulating unit is specially designed for heavy-duty commercial applications, and it’s gas-fired. Therefore, it provides hot water on demand while using optionally sealed combustion and power-vented flue, while allowing both indoor and outdoor installation.

The design is smart since the unit comes with computerized safety features and no pilot light. It produces hot water for hydronic heating systems, re-circulation systems, radiant floor heating systems, and/or combined domestic and heating applications. It allows both horizontal and vertical installation and has electronic ignition.

The compact profile is going to ensure space-saving, whereas the 56dB noise level at maximum output means quiet operation. It’s strong enough for producing hot water for six bathrooms in warm climates.

Here are the best parts of the unit:

  • The unit runs on natural gas and is ASME approved
  • It’s energy-efficient and reliable
  • It comes with computerized safety features
  • It’s made for heavy-duty commercial applications

Let’s take a look at the downsides as well:

  • Some experienced leakage issues
  • It’s not cheap

There’s no such thing as the perfect commercial tankless water heater. Nevertheless,  this one does come close to being one, and it’s worth every single penny.

FAQs on commercial tankless water heaters

Q: Do commercial tankless water heater pose any safety issues?

A: The majority of commercial tankless water heaters are made with overheating and overpressure protection systems. Should anything go wrong, the systems are going to shut off automatically or inform you about the malfunction.

Q: Is it effortless to install a commercial tankless water heater?

A: A tankless water heater may be installed right in the bathroom, eliminating the need for breaking the wall. Suitable units come with several buttons for adjusting the water heater and safety features that ensure secure use.

Q: Can one tankless water heater work in a large hotel or hospital?

A: Because of the high demand for hot water and power, just one commercial tankless water heater may not be powerful enough for providing hot water in a large hotel or commercial application. Therefore, several units are going to have to be connected. It’s recommended that you get professional help for installing the units.

Q: Which are the critical areas of high water consumption in a hotel?

A: In the case of hotels, five key areas present high water consumption. The kitchen, guest rooms, staff areas, pool area (if there’s one), and the laundry machines are the areas where tankless water heaters should be installed.

To give you an example, an average faucet can pump water at 2.5GPMP, which isn’t efficient for a hotel. With guests not being concerned about the utility bill, the risk for guests to also leave the sink running is quite high. Installing a flow-low faucet and an electric tankless water heater will cut down the energy bill and limit the water flow to 0.5 to 1GPM.

Q: Does the water quality also matters for commercial applications?

A: Even if contractors are aware of the local water conditions, it’s always important to consider the hardness of the water. 85% of the communities in the U.S. have hard water. Therefore the local water supply should be more than 12 grains of dissolved magnesium, calcium, and manganese in every gallon. The heat exchanges in tankless units are more sensitive to water quality than tank models, which is why the hardness of water matters more.

Contractors always have to know about the qualities of water supply in the service area so that the warranties don’t get void on the cause of hard water.

Q: Are commercial tankless water heaters expensive to take care of?

A: More often than not, the businesses are looking for a system that doesn’t require much maintenance or service. With commercial tankless water heaters needing descaling once or twice a year, support doesn’t come cheap. However, they don’t need routine descaling and only require a visual inspection of the venting connections, eliminating the need for service. Tankless descaling is around $250 per unit, which is affordable, considering the lower energy spending.

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