Rinnai CU199I Lp to Natural Gas Conversion Kit

Product Description

The RINNAI CU199I LP to natural gas conversion kit provides all components required to convert a 199-class indoor tankless water heater from liquid propane to natural gas operation. Manufacturer part number RI-103000076, this kit includes a calibrated orifice set, conversion regulator components, screws, seals, and natural gas configuration labeling for appliance documentation. The hardware is engineered to match the combustion-air settings, burner geometry, and modulation logic of the 199-class platform, ensuring correct gas-air ratios across the full firing range. Licensed gas technicians and plumbers perform this conversion during equipment commissioning or fuel-source changeovers.

This kit is designed for indoor 199-size tankless units where the fuel supply is being changed from liquid propane to natural gas. Compatible units include the RU199i, RUR199i, and CU199i models. Before installation, the technician must confirm the unit is one of these indoor models and verify that inlet pressure, venting configuration, and gas supply capacity meet natural gas requirements after conversion. This kit is not intended for outdoor units or for smaller capacity tankless platforms.

Key Features

• Calibrated orifice set sized for natural gas operation across the full modulation range
• Includes conversion regulator components, screws, and seals for a complete conversion
• Natural gas configuration labeling documents the fuel change at the appliance
• Engineered to maintain correct combustion-air ratios and stable ignition under natural gas
• Designed specifically for the 199-class indoor tankless platform

Compatibility

Compatible with Rinnai indoor tankless units RU199i, RUR199i, and CU199i. This kit converts those units from liquid propane to natural gas and is not for use with any other model or fuel conversion direction.

Installation Notes

Installation must be performed by a licensed plumber or gas technician in accordance with local codes, the International Fuel Gas Code (IFGC), and Rinnai manufacturer specifications. Shut off and lock out the gas supply before disassembling any burner or regulator components. Verify natural gas inlet pressure and supply capacity meet unit requirements before and after conversion. After reassembly, perform a leak check on all gas connections and confirm proper ignition, flame characteristics, and modulation before returning the unit to service.

Technical Specifications

• Conversion Direction: Liquid Propane to Natural Gas
• Compatible Platform: 199-class indoor tankless water heater
• Includes: Calibrated orifice set, regulator components, screws, seals, NG configuration labeling

Standard Information

• Brand: RINNAI
• Manufacturer Part Number: CU199I