Best Commercial Tankless Water Heaters for Restaurants

Best Commercial Tankless Water Heaters for Restaurants (September 2023)🥇

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Charlie W. Palmer
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Last Updated: 28 September 2023


In this article, we’re going to be discussing the best commercial tankless water heaters for restaurants, that are available on the market.


✅Why use a tankless commercial water heater?

According to a study carried out by Consumer Reports, commercial tankless water heaters, including electric and gas units are an energy-efficient way of getting hot water. Their ability to process large amounts of water without storing it allows these models to consume 22% less energy than tank-carrying water heaters.

Their space-saving design is another notable feature of tankless heaters. Since they don’t have to use tanks to store water, these products can afford to be small and compact. That’s precisely the reason why you can install them in tight spaces with minimal fuss.

On top of everything else, these units justify their high initial asking price by delivering a constant supply of hot water. When a hot water tap is opened, an electric element or gas burner heats the water as it travels through the pipe. That means you won’t have to wait to get hot water at the tap.


💧Top Considerations Before Purchasing

  • Technical Specs – We’ve done our very best to outline each heater’s technical specs, including thermal efficiency, flow rate (GPM), energy factor and temperature range, so you have all of this information available when making any comparisons between models.
  • General Specs – We’ve also included information regarding the units physical dimensions and weight
    • Price – Price information has also been specified, with $ representing the lowest price and $$$$$ representing the highest. We realize that everyone has a unique budget, so this is an important consideration.
    • Warranty – We’ve displayed warranty information where possible.
  • Customer Reviews/Ratings – We’ve gone about researching only the highest quality tankless water heaters to include within this article, therefore you can be confident in knowing that any of these units are a great choice.



Best Commercial Tankless Water Heaters for Restaurants Review – Top 3

  • Rinnai RUCS75iN Natural Gas Tankless Hot Water Heater – 5GPM – $$$$ Skip to Product
  • Rinnai RUCS75iP Propane Tankless Hot Water Heater – 7GPM – $$$$ Skip to Product
  • AO Smith ATI-540H-N Condensing Residential/Light Commercial Tankless Heater – 10GPM – $$$$ Skip to Product



Rinnai RUCS75iN Natural Gas Tankless Hot Water Heater


The Rinnai RUCS75iN Series SE tankless water heater is made for indoor installation only. It works best in a warm climate and in an area that is shielded from bad elements of weather. You can count on it to deliver the goods as long as it isn’t freezing out there.

Technical Specs

  • BTU: 10,300 – 160,000
  • Thermal Efficiency: 99%
  • Flow Rate (GPM): 5 GPM
  • Energy Factor: 93
  • Installation: Indoor Only

General Specs

  • Price: $$$$
  • Dimensions: 1 (D) x 31.1 (H) x 18.5 (W) inches
  • Weight: 3 pounds
  • Warranty: 12 year/5 year/1 year


There are some models on the market whose unique selling point is their extreme efficiency. The RUCS75iN isn’t one of them. This unit’s huge flow-rate of 7.5 GPM is as impressive as its 0.93 energy factor. That means it delivers impressive money savings while also providing bucket-loads of hot water.

It is equipped with ThermaCirc360 technology that keeps on recirculating hot water through the pipes. This makes sure that you get the water the moment you open the tap. There won’t be any waiting time during which you have to do nothing but stare at the tap.

That this model has a compact design means you can install it in non-traditional spaces. It would quickly get under your attic, in the crawl space and even inside the closet. Also on offer is a compatible mobile app using which you can schedule timers and put the system into vacation mode.

  • Huge flow rate
  • 12 year residential/factory warranty
  • Compatible with a mobile app
  • Minimal waiting time for hot water
  • Vent kit has to be purchased separately




Rinnai RUCS75iP Propane Tankless Hot Water Heater



Posing yourself as an alternative to one of the best-selling tankless water heaters is one thing. Justifying that claim is an altogether different ball game. That’s precisely what the iSpring RCB3P water filter system does. Though you’d have to pay over the odds to take advantage of what it has to offer.

 Technical Specs

  • BTU: 10,300 – 160,000
  • Thermal Efficiency: 93%
  • Flow Rate (GPM): 7 GPM
  • Energy Factor: 90
  • Installation: Indoor Only

General Specs

  • Price: $$$$
  • Dimensions: 1 (D) x 31.1 (H) x 18.5 (W) inches
  • Weight: 3 pounds
  • Warranty: 12 year/5 year/1 year


Wondering what is it that separates this model from the abovementioned Rinnai? Multiple features set apart the duo. This one runs on propane gas and is therefore recommended for those of you who live in far-flung areas where the supply of natural gas is impossible.

However, that doesn’t mean that you should ignore this model if you have a natural gas line coming to your home. That decision will deprive you of the extra 0.2 gallons per minute of hot water that this unit provides (7.7 GPM) vis-à-vis the RUCS75iN water heater.

Similar to its low-capacity counterpart, you can operate this model as well with a Control-R 2.0 mobile app. It features timers and schedules to help you pre-program this unit in advance. You can also activate a ‘vacation mode’ using the app that will put the heater to sleep.

  • Endless supply of hot water
  • Cinch to install
  • Slim and compact
  • Runs on propane




AO Smith ATI-540H-N Condensing Residential/Light Commercial Tankless Heater



Most tankless heaters you see on the market pay extra attention to their flow rate and efficiency. Some care about secondary things like ease of installation and all that. The AO Smith ATI-540H-N belongs to the minority that places equal emphasis on both.

Technical Specs

  • BTU: 10,300 – 199,000
  • Thermal Efficiency: 93%
  • Flow Rate (GPM): 10 GPM
  • Energy Factor: 95
  • Installation: Indoor Only

General Specs

  • Price: $$$$
  • Dimensions: 5 x 18.5 x 29.5 inches
  • Weight: 59 pound
  • Warranty: 12 year/5 year/5 year


Those of you who thought that its anonymous brand name would force this heater to come cheap are wrong. It is charging for its features and not the name on the package. Some of those features, like the overheat cutoff fuse, are what we come to expect from models costing this much.

Others, like the air-fuel ratio sensor that ensures optimum combustion and minimizes wastage of energy, are unexpected. Similar is the case with its exhaust safety valve that prevents the build-up of gases and the water temperature safety control that minimizes the chance of bursting of pipes.

Its flow rate of 10 gallons per minute is at least 2.5 GPM more than offered by any heater that we have seen thus far. Equally unprecedented is the 5-year warranty that this model gives on parts – as most heaters which cost this much lure their users with a lower, 3-year warranty.

  • Air-fuel ratio sensor
  • Overheat cutoff fuse
  • Massive flow rate
  • Have to wait for hot water





Frequently Asked Questions

Here are some of the FAQs related to commercial tankless water heaters:


🚰What’s the cost of a commercial tankless water heater for a restaurant?

The cost of a restaurant commercial tankless water heater is approximately $1000. This will vary slightly from brand to brand, but the products that we’ve recommended above are priced around this amount.


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Commercial Tankless Water Heaters for Restaurants
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Commercial Tankless Water Heaters for Restaurants
Hi! I'm Charlie. If you're wondering why I started WaterSystemsGuide, it's because I previously worked as a water systems specialist/consultant for a large government initiative in California, USA. However, after leaving, I wanted to provide advice and information for others, to pass my knowledge on, so I created this site!
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