Enviroment: Local
Commercial Tankless Water Heater

Commercial Water Heating Solutions

Sometimes the difference between "open for business" and "closed for repairs" is the reliability of a water heating system.

That's why for decades, a full spectrum of commercial applications - from retrofit to new construction and light to heavy - have trusted Rinnai Tankless Water Heaters. Because the system configures to your needs and to every kind of space, every usage demand is the perfect Rinnai fit - and that makes it easy to do business.

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Demand Duo™ Satisfaction Guarantee

If you are not 100% satisfied with the Demand Duo within the first 30 days after installation, or the unit does not perform as stated, Rinnai will replace the Demand Duo with a comparable product at Rinnai’s expense.*

Please contact us at rinnaicustomercare@rinnai.us for more information.

See Rinnai Demand Duo™ In Action

The Demand Duo™: Built for commercial

This unique Commercial Hybrid system combines all the benefits of the Rinnai C199 Condensing Tankless Water Heater with a 119-gallon storage tank and provides a direct replacement for most traditional and high efficiency commercial tanks. Along with Rinnai’s reputation for quality and reliability, all parts are replaceable and easily serviced. The result is a superior performing product designed to reduce the need for frequent tank replacements.

Note: All tests were conducted with a fully charged tank set at 140°F. This was a draw only test with no recovery. High efficiency tanks 100 gallons, standard efficiency 80 gallons; 40° F supply water temperature.

Connection Locations:

  1. Electrical
  2. Gas
  3. Cold Supply
  4. Hot Supply
  5. Concentric Vent Intake / Exhaust
  6. Two Pipe Combustion Air Intake
  7. Tank T&P
  8. Tank Drain Valve
  9. Condensate Drain (behind cover)
  10. Temperature Controller
  11. Tankless PRV

Continuous draw performance charts

Internal tests were conducted to show temperature ranges and volume of hot water at a specific GPM draw.

1 GPM Data:Rinnai provides stable temps

6 GPM Data:Rinnai provides stable temps and more hot water

8 GPM Data:Rinnai provides stable temps and more hot water

High Efficiency Tank (100 Gallon)

Standard Efficiency Tank (80 Gallon)
Rinnai Demand Duo™ (119 Gallon)

The New Rinnai Demand Duo Commercial Hybrid System

Hot water heating's big performance, business-friendly solution

You spend your business day multi-tasking – why shouldn’t your commercial hot water system do the same? Introducing the Demand Duo™ – the perfect solution for direct replacement of most traditional standard and high efficiency commercial tanks. And Rinnai backs it’s nearly 100-year reputation of quality and reliability with a 6-year HEX/Tank warranty.* The all new Rinnai Demand Duo™ is a master multi-tasker you’re sure to admire.

Demand and Supply

Combining the on-demand, continuous supply technology of the Rinnai C199 tankless with an energy efficient and durable 119-gallon storage tank, the Demand Duo™ provides more water-heating capacity than a traditional tank in the first hour. The result: Hot water is available to keep pace with demand – from short-period, high-spike draws, to a supply that’s ready to go the distance, day in and day out.

Ultimate Efficiency

Equipped with the all new C199 Tankless Water Heater which is Commercial ENERGY STAR® certified, has 96 percent thermal efficiency, 199,000 BTU, fueled by either Natural Gas or Propane, the Demand Duo™ produces consistent water temperatures for predictably smooth business operations. Optimum performance is achieved by efficient tank recovery methods so you can count on having hot water even during reheat cycles.

Strength In Numbers

With the ability to install multiple Demand Duos™ together, we create redundancy that keeps hot water flowing – and your business going.

Peace-of-Mind Monitoring

The effort to keep hot water availability and business uptime high doesn’t stop with the hybrid system itself. The Demand Duo™ can also tie into a building management system with the DPS/MIS accessory, ending alerts when the system needs attention. In addition, the maintenance alert system on the Rinnai built-in controller provides peaceof-mind monitoring protection to put the efficiency and performance of your hot water on cruise control.

Demand Duos™ Highlights:

  • Warranty: 6-year heat exchanger / tank, 5-year parts and up to 2 years labor*
  • Built standard with C199 Commercial Tankless Water Heater
    • Commercial ENERGY STAR® certified with 96% Thermal Efficiency
    • Ultra Low NOx compliant
    • 199,000 BTU
  • Approved for high altitude up to 10,200 ft (3,109 m)
  • Integrated temperature controller that provides 98°F to 185°F (no external controller required)
  • Fueled by Natural Gas or Liquid Propane
  • Assembled with individually certified components
  • First Hour Rating: 315 gal / Recovery: 231 gal (@ 100°F ΔT)
  • Multiple venting options (concentric, two pipe, room air, common vent)
  • Perfect for emergency replacement situations – connection locations similar to most popular high efficiency tanks
  • Easy and cost effective maintenance – all parts replaceable

* The Demand Duo is backed by our limited warranty. Click here for complete details. In addition, we are so sure you’ll be happy with your purchase that we offer a “No Risk Performance Satisfaction Guarantee”. Specifically, Rinnai guarantees that its Demand Duo will perform to specification. If within the first 30 days after installation you find it does not perform as stated and you are not 100% satisfied with the Demand Duo, Rinnai will remove the Demand Duo and provide a comparable replacement product including installation labor. Rinnai reserves the right to verify correct installation prior to product replacement. Simply contact us at rinnaicustomercare@rinnai.us to speak to a customer care specialist about our “No Risk Performance Satisfaction Guarantee”. This guarantee is valid for all Rinnai Demand Duo units installed between August 15, 2016 and June 30, 2017.

** For complete information and details regarding Rinnai’s warranty, visit rinnai.us/warranty.