Rheem IKONIC S 11.2 GPM 199,900 BTU Liquid Propane Indoor Condensing Tankless Water Heater (.96 UEF)

High-Efficiency Tankless Water Heater Delivering 11.2 GPM

The Rheem IKONIC S Series Tankless Water Heater provides high-efficiency on-demand hot water with a maximum gas input of 199,900 BTU/h, a maximum flow rate of 11.2 GPM at a 35°F temperature rise, and a 0.96 Uniform Energy Factor (UEF).

Designed for easy installation and retrofit applications, the unit supports PVC vent runs up to 70 feet with 2-inch venting or 150 feet with 3-inch venting. It also allows flex venting through existing B-vent up to 50 feet and features a full-text digital display for simplified setup without dip-switches.

Key Benefits

• High Heating Capacity: Provides up to 199,900 BTU/h maximum gas input for residential on-demand water heating.
• On-Demand Hot Water: Delivers up to 11.2 GPM at a 35°F temperature rise. Actual flow rate varies with incoming water temperature and the required temperature rise.
• High-Efficiency Performance: Features a Uniform Energy Factor (UEF) of 0.96.
• Stainless Steel Heat Exchangers: Features stainless steel primary and secondary heat exchangers designed to support efficient water heating and durability.
• Hot-Start Programming™: Helps keep the unit ready between back-to-back hot water uses, helping avoid cold-water bursts.
• Simplified Setup: Features a full-text digital display and setup without dip switches.
• Retrofit-Friendly Venting: Allows approved flexible venting through an existing B-vent up to 50 feet, subject to Rheem's installation requirements. Verify vent compatibility and configuration before installation.
• 1/2-Inch Gas-Line Compatibility: Supports 1/2-inch gas-line installations where permitted by local code. A qualified installer must verify gas-line sizing and supply capacity for the liquid propane installation. The unit's gas connection is 3/4-inch NPT.
• Manufactured Home Approved: Approved for manufactured-home installations, subject to Rheem's installation instructions and applicable local codes.

Understanding Tankless Water Heater Sizing

The RECTGH-S11iP provides a maximum flow rate of 11.2 GPM at a 35°F temperature rise. At a 45°F temperature rise, the maximum flow rate is 8.8 GPM, while a 67°F temperature rise provides a maximum flow rate of 5.9 GPM.

Flow rates vary depending on the temperature of incoming cold water and the water heater set temperature. The capacity information provides flow-rate guidance based on different groundwater temperature zones.

How to Calculate Temperature Rise

To determine temperature rise, subtract the incoming water temperature from your desired hot water temperature. For example, if the incoming water temperature is 55°F and the desired hot water temperature is 120°F:

120°F - 55°F = 65°F Temperature Rise

Refer to the Water Flow (GPM) chart below to compare estimated flow rates at different temperature rises and assess whether the Rheem IKONIC S11i can meet your household's hot water demand. Available flow rate decreases as the required temperature rise increases. Actual performance depends on incoming water temperature, the selected water temperature, and operating conditions. Chart values are estimates for sizing purposes.

Energy Efficiency & Performance

• Uniform Energy Factor (UEF): 0.96
• Maximum Flow Rate: 11.2 GPM at a 35°F temperature rise
• Gas Input: Up to 199,900 BTU/h

Actual hot water flow depends on the incoming water temperature and the required temperature rise.

Warranty

Rheem provides a 15-year heat exchanger warranty, 5-year parts warranty, and 1-year labor warranty for single-family residential installations.

Important Warranty Conditions:

• Residential Use: Standard residential installations qualify for full coverage. Commercial installations receive 5-year heat exchanger and parts coverage.
• Recirculation Systems: Controlled recirculation qualifies for full residential coverage. Uncontrolled, continuously operating recirculation reduces heat exchanger and parts coverage to 3 years.
• Operating Hours: All warranty coverage ends after 12,000 hours of operation.
• Installation & Maintenance: Damage from improper installation, mineral buildup, scale, or water quality outside Rheem's specified limits is excluded.
• Labor Coverage: Covers reasonable labor costs for covered repairs during the first year when performed by a licensed, qualified contractor trained on Rheem tankless water heaters.
• Ownership: Warranty applies only to the original owner at the original installation location and is nontransferable.

Warranty coverage begins on the documented installation date. Without documentation, coverage begins 90 days after manufacture. Product registration does not extend the warranty period.

Review Rheem's official Limited Warranty Certificate for complete terms, exclusions, and coverage details.

What's Included

• Rheem IKONIC S11i tankless water heater
• Brass service valves
• Pressure relief valve
• LP to NG gas conversion kit
• 5-foot, 120V, 3-prong power cord
• Mounting and spare-parts kit
• Vent screens
• Use and care manual

Requirements & Considerations

• Fuel Type: Factory-configured for liquid propane (LP) and includes a natural gas (NG) conversion kit for qualified field installation..
• Installation Type: Indoor installation. The outdoor conversion kit is sold separately.
• Venting: Use approved vent materials and configurations according to Rheem's installation instructions.
• Gas, Water & Condensate Connections: Follow the installation manual for connection sizes and requirements.
• Clearances: Maintain the clearances specified in the installation manual for safe operation and service access.
• Wi-Fi: Standard included feature for the S11i model.