RX199IN 199,000 BTU, Condensing Indoor/Outdoor Tankless Water Heater (Natural Gas or Propane)

Rinnai RX199IN 199,000 BTU Condensing Indoor/Outdoor Tankless Water Heater (Natural Gas or Propane)

The Rinnai SENSEI RX199IN is a condensing tankless water heater rated at 199,000 BTU maximum input, compatible with both natural gas and propane fuel types. This compact unit delivers 0.98 Uniform Energy Factor efficiency and can be installed indoors or outdoors using the RX Series Outdoor Vent Cap RXOVC (sold separately). The heater operates on 120 volts and provides hot water on demand without the standby energy losses of traditional tank systems. The unit is only the size of a small suitcase.

Key Features & Benefits

• High Thermal Efficiency: 97% thermal efficiency captures more heat from combustion gases, reducing fuel consumption.
• Ultra-High Efficiency Rating: 0.98 Uniform Energy Factor (UEF) delivers maximum energy savings.
• Energy Star Certified: Meets EPA energy efficiency standards for reduced environmental impact and potential utility rebates.
• Variable BTU Range: 15,000 to 199,000 BTU per hour input range modulates precisely to match hot water demand.
• Wide Temperature Control: Adjustable output from 98°F to 120°F accommodates diverse household needs.
• High Flow Capacity: 0.13 to 11.1 gallons per minute flow range serves multiple simultaneous fixtures.
• Temperature Rise Performance: Delivers 9.7 GPM at 40°F rise, 7.8 GPM at 50°F rise, 6.5 GPM at 60°F rise, and 5.5 GPM at 70°F rise.
• Dual Installation Capability: Indoor and outdoor installation options (outdoor requires RXOVC vent cap, purchased separately).
• Concentric Venting: Concentric vent design simplifies installation with single-penetration venting using PVC.
• WiFi Connectivity: Integrated wireless control allows remote temperature adjustment and system monitoring.
• AHRI Certified: Air-Conditioning, Heating & Refrigeration Institute certification verifies published performance ratings.
• CSA 4.3 Certified: Meets Canadian Standards Association water heater safety and performance standards.
• Compact Footprint: Small suitcase-sized cabinet fits in tight mechanical spaces.
• Extended Lifespan: Lasts up to twice as long as conventional tank water heaters with twice the warranty length of tank models.
• Residential Application: Designed specifically for residential hot water demands.
• Standard Connections: 3/4-inch NPTM cold water inlet, 3/4-inch NPTF hot water outlet, 3/4-inch gas connection.
• Saves energy by heating water only when it is needed.

Compatibility & Requirements

For outdoor installations, the RX Series Outdoor Vent Cap RXOVC must be purchased separately. The Rinnai MIVK-T-LW Water Heater Isolation Valve Kit is no longer provided with the unit and must be purchased separately. Installation should be performed by a qualified installer in accordance with local codes. Verify gas supply pressure and volume meet the unit's requirements for the selected fuel type (natural gas or propane). You may be eligible for rebates from your local utility company and state; search your zip code at the Rinnai Rebate Center for information about local rebate programs that may apply to you. Ensure adequate combustion air supply and proper venting materials (concentric or separate PVC/CPVC) per code requirements. Unit replaces models RU199EP, RUC98IN, RU98IN, RU199IN, RC98HPEN, RU199IP, RU98EN, and RU199EN. Indoor and outdoor compatible with use of RX Series Outdoor Vent Cap RXOVC, purchased separately.

Installation & Care

Mount the unit securely on an interior or exterior wall following the spacing and clearance requirements. Connect 3/4-inch cold water inlet, hot water outlet, and gas supply lines using approved materials and methods. Install the concentric vent assembly or separate air intake and exhaust vents using approved PVC or CPVC pipe with proper slope for condensate drainage. Wire the 120-volt electrical supply to the unit's connection terminals. Set fuel type (natural gas or propane) using the unit's control interface. Adjust temperature setpoint between 98°F and 120°F as desired. Replace air supply filters periodically to maintain combustion efficiency and prevent premature component failure. Flush the heat exchanger annually in areas with hard water to prevent scale buildup. Inspect venting system terminations for blockages or damage. In freezing climates, verify freeze protection heaters are functioning when the unit is installed indoors.

What's Included

• RX199IN tankless water heater
• Remote control harness
• Freeze protection heater for heat exchanger
• Secondary heat exchanger freeze protection heater
• Freeze protection valve heater
• Air supply filters (set)
• Front cover
• Installation hardware

Warranty & Support

The RX199IN carries a 15-year limited warranty on the heat exchanger or 12,000 hours of operation, whichever occurs first. Parts are covered under a 5-year limited warranty. Labor is covered under a 1-year limited warranty from the date of installation. Warranty terms apply when the unit is installed by a qualified installer and maintained per specifications.

Frequently Asked Questions

Q: What size gas line is required and can 2-inch venting be used instead of 3-inch?
A: This unit has a 3/4-inch gas connection. The vent diameter can be reduced from 3 inches to 2 inches, but cannot be less than 2 inches.

Q: Does the RX199IN have a built-in recirculation feature for faster hot water delivery?
A: The RX199IN does not include a built-in recirculation pump or thermal bypass valve; for that feature, see the RXP199IN model.