Product Description
The RINNAI CHS199100CUIN is a commercial-grade hybrid tankless water heater in the H-Series Demand Duo line, designed for facilities that require continuous, on-demand hot water with built-in redundancy. Running on natural gas, it delivers a maximum output of 199,000 BTU/h and a minimum modulation down to 15,000 BTU/h, giving installers a wide firing range to match varying load demands. At 97% thermal efficiency, this unit is engineered to lower fuel consumption and reduce the long-term cost of operation in high-demand commercial settings. Licensed plumbers and mechanical contractors typically handle specification and installation of this class of equipment.
The CHS199100CUIN is built for commercial applications where a single point of failure in the water heating system is unacceptable. The Demand Duo configuration pairs hybrid tankless technology with a redundancy framework, making it well suited for hotels, multi-family housing, restaurants, and light industrial facilities. Its wide modulation range allows the unit to right-size heat output to current demand rather than cycling on and off at full fire, which reduces wear and supports consistent outlet temperatures throughout the day.
Key Features
- Maximum output of 199,000 BTU/h with low-end modulation to 15,000 BTU/h for broad load coverage
- 97% thermal efficiency reduces fuel costs in continuous commercial operation
- H-Series Demand Duo design provides built-in redundancy for uninterrupted hot water supply
- Natural gas fuel type compatible with standard commercial gas service
- Hybrid tankless configuration combines on-demand heating with commercial reliability features
Compatibility
Designed as an OEM commercial hybrid tankless water heater replacement or new-installation unit within the RINNAI H-Series Demand Duo product family. Consult the full specification sheet and local mechanical codes to confirm compatibility with existing gas supply, venting, and water system configurations before ordering.
Installation Notes
Installation must be performed by a licensed plumber or mechanical contractor in accordance with local plumbing codes, the International Fuel Gas Code (IFGC), and the manufacturer installation manual. Shut off the gas supply and cold water inlet before making any connections or servicing the unit. Verify that the existing gas line size, pressure, and venting system meet the requirements specified in the installation documentation. Do not exceed the maximum gas inlet pressure listed in the product manual, and confirm that all venting is routed and terminated per applicable codes before commissioning.
Technical Specifications
- Product Type: Tankless Water Heater
- Fuel Type: Natural Gas
- BTU/h (Maximum): 199,000
- BTU/h (Minimum): 15,000
- Thermal Efficiency: 97%
- Height: 34.5 inches
- Width: 30.8 inches
- Depth: 69.3 inches
Standard Information
- Brand: RINNAI
- Manufacturer Part Number: CHS199100CUIN
Why buy from Doctor Paintz
- Sold and shipped by Doctor Paintz – doctorpaintz.us
- Brand-new, factory-sealed stock – never reclaimed or refilled
- Trade pricing and bulk/pallet quantities for HVAC contractors
- US-based order support, tracked shipping on every order

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