Commercial Tankless Water Heater

Commercial Water Heating Solutions


Rinnai Tankless Water Heaters produce an endless supply of hot water to suit even the most demanding applications—from restaurants to hotels to multifamily residences to schools and more.

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Solutions for any application, perfectly designed.

Reliable Rinnai Tankless Water Heaters deliver solutions for a full spectrum of commercial applications—from retrofit to new construction and light to heavy. Because the system configures to your needs, every kind of space, every usage demand is the perfect Rinnai fit—and that makes it easy to do business.

Thanks to our flexible venting options and Tankless Rack System, as well as solutions that are custom designed (with and without storage), you can use multiple units together to provide anywhere from 15,200 to 4.9 million BTU—enough to replace even large boilers.

County Courthouse: TRS06i with Common Vent (1.2M BTU)

63-Unit Multi-Family Residence: TRS06e (1.2M BTU)


  • Restaurants
  • Hotels & Hospitality
  • Healthcare Facilities
  • Schools/Universities
  • Office Buildings
  • Apartment Buildings

The Proof is in the performance.

Rinnai Tankless Water Heater Case Studies



  • Multiple showers, sinks, washing machines and kitchen appliances used at once
  • Peak usage hours with high demand; other periods of time with low use
  • Existing system was 2M BTU condensing boiler and 725-gallon storage tank


  • Installed an interior Rinnai Tankless Rack System rated 1.2M BTU with Rinnai’s Common Vent system
  • Fully modulating system with a 78:1 turn-down ratio capable of meeting fluctuating demand
  • Operated only when needed, saving energy during low demand
  • Experienced less than two hours of downtime in the transition



  • Conducted a one-year study to compare tank- style water heaters to tankless water heaters in six restaurants across America
  • One restaurant from each region installed a Rinnai Tankless Rack System with four tankless units, while another from each region installed a tank-style water heater


  • On average, gas usage was approximately 21% less with tankless
  • Each of the three restaurants who used tankless saw an average energy savings of $5,820 for the year
  • With 1,100 locations nationwide, using Rinnai Tankless Water Heaters could save this chain as much as $6.4 million a year



  • High-demand multi-family project with 63 units
  • Existing system included two large boilers at 500K BTU each and a 270-gallon storage tank


  • Installed an exterior Rinnai Tankless Rack System (six tankless water heaters) rated at 1.2M BTU
  • Installation on rooftop took only a half day and was less expensive than what was originally specified



  • Two schools with similar hot water system designs
  • One outfitted with tank-style water heaters and one with Rinnai Tankless Water Heaters


  • Rinnai Tankless Water Heaters saved 5.2 to 6.4 cents* per gallon of water used compared to tank-style units
  • Potential annual savings of $1,400
  • Energy consumption reduced by more than 70% compared to tank-style units

* Based on a price of $1.60 per therm.