Best for Quick Replacements
Demand Duo® is great for emergency replacement and high-capacity needs because it has the storage capacity of a tank paired with the energy efficiency and longer life of a tankless.
Demand Duo® Benefits
![Tankless Water Heater](https://staging.rinnai.ca/sites/default/files/styles/large/public/2021-02/c-duo_1.jpg)
Flexible Installation
Features a preassembled gas connection with an installed drip leg and swivel flex line allowing for quick and hassle-free installation.
![DuoSmart](https://staging.rinnai.ca/sites/default/files/styles/large/public/2021-02/c-duo_2_duoSmart.jpg)
DuoSmart Delivers
Demand Duo® uses DuoSmart Tank Technology™ to deliver more value than standard tanks, including a lower cost of ownership, energy-saving performance, and abundant hot water when you need it.
![Optimized Controller](https://staging.rinnai.ca/sites/default/files/styles/large/public/2021-03/CHS19980H_Overall0003.jpg)
Optimized Controller
The new digital controller can manage building circulation, eliminating the need for a separate aquastat.
How it Works
Greater Capacity and Lifespan
The Rinnai Demand Duo® pairs a durable 119-gallon tank with a Rinnai CU199 tankless unit.
- A direct replacement with connections similar to most high-efficiency tanks.
- Simple to install and keeps pace with an establishment’s hot water needs.
Demand Duo® Solutions
Demand Duo®
H-Series
Bringing a multitude of installation options as well as an upgraded recovery pump for improved tank recovery time.
- Choice of multiple tankless and tank options
- Preassembled electric and gas connections
- Set building recirculation and temperature setpoint with the Digital Controller
![H series](https://staging.rinnai.ca/sites/default/files/styles/scale_width_200px/public/2021-02/h-series.png)
Demand Duo®
R-Series
Our newest line of commercial hybrid water heaters brings the performance, versatility and reliability from Rinnai. And it's backed by the industry's best warranty.
- No new vent runs or structure penetrations required
- Longer lifespan with no thermal stress on tank
- Easily connect to existing 6" B-Vent
![Demand Duo R-Series 100](https://staging.rinnai.ca/sites/default/files/styles/scale_width_200px/public/2023-03/Demand-Duo_100R_hero_image.png)
Demand Duo® 2V
Combining the redundancy and performance of our tankless rack systems with the hybrid technology of Demand Duo®.
- Built-in redundancy for reliable hot water
- Cutting-edge technology that’s easy to maintain
- ASME certified option available
![Demand Duo™ 2V](https://staging.rinnai.ca/sites/default/files/styles/scale_width_200px/public/2021-02/demandduo-2v.png)