Rinnai REP199iN Smart-Circ Natural Gas Tankless Water Heater User Manual

1. Product Overview

The Rinnai REP199iN Smart-Circ Non-Condensing Natural Gas Tankless Water Heater is designed for indoor installation, providing on-demand hot water with a built-in recirculation pump. This model features Smart-Circ technology, which learns your household's hot water usage patterns to optimize recirculation, reducing wait times and conserving energy. Its compact design allows for installation in various spaces, offering a continuous supply of hot water for residential use.

Figure 1: Front view of the Rinnai REP199iN Tankless Water Heater.

2. Safety Information

WARNING: Improper installation, adjustment, alteration, service, or maintenance can cause property damage, injury, or death. Read the installation, operating, and maintenance instructions thoroughly before installing or servicing this equipment.

• This appliance must be installed by a qualified professional in accordance with all local codes and regulations.
• Ensure adequate ventilation as specified in the installation manual.
• Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.
• Verify that the gas supply type (Natural Gas) matches the appliance requirements.
• Keep the area around the water heater clear of combustible materials.

3. Setup and Installation

Professional installation is strongly recommended for the Rinnai REP199iN water heater. Refer to the comprehensive installation manual provided with the unit for detailed instructions and diagrams. Key considerations include:

• Location: This model is designed for indoor installation. Ensure the chosen location meets clearance requirements and has proper ventilation. The compact size (14.05"W x 27.24"H) allows for flexible placement.
• Mounting: The unit is wall-mounted. Ensure the mounting surface is structurally sound to support the unit's weight (approximately 24.04 kg).
• Gas and Water Connections: Proper sizing and connection of natural gas and water lines are critical. Use appropriate fittings and ensure all connections are leak-free.
• Ventilation/Exhaust: An appropriate exhaust pipe system is required. Rinnai-specific exhaust components are recommended for optimal performance and safety. Plan for exhaust pipe installation before mounting the unit.
• Electrical Connection: The unit requires a 120 Volt electrical supply.

Figure 2: Example of an indoor Rinnai tankless water heater installation.

Figure 3: Rear view of the Rinnai REP199iN unit, highlighting connection points.

Figure 4: Side view of the Rinnai REP199iN showing the digital display and controls.

4. Operating Instructions

The Rinnai REP199iN operates on an on-demand principle, heating water only when a hot water tap is opened. This ensures an endless supply of hot water without the need for a storage tank.

• Smart-Circ Intelligent Recirculation: The built-in recirculation pump, combined with Smart-Circ technology, learns your hot water usage patterns. It anticipates demand and circulates hot water proactively, reducing wait times at the tap.
• Temperature Control: The unit's digital display allows for precise temperature setting, up to a maximum of 140 degrees Fahrenheit.
• Flow Rate: This model provides up to 7.9 Gallons Per Minute (GPM), capable of supplying hot water to multiple fixtures simultaneously (e.g., up to 6 fixtures at once).
• WiFi Connectivity (Optional): The unit can be made smarter with a Rinnai Controlr module (not included) for WiFi control and remote monitoring.

Figure 5: Tankless water heater operation, heating water as it flows through the unit.

Figure 6: Illustration of the recirculation technology, ensuring hot water is readily available.

5. Maintenance

Regular maintenance is essential to ensure the longevity and efficient operation of your Rinnai tankless water heater. Annual maintenance is recommended.

• Descaling: Annually descale the unit to remove mineral buildup, especially in areas with hard water. This process typically involves circulating a descaling solution through the heat exchanger. Consult the full manual for detailed descaling procedures or contact a qualified technician.
• Ventilation Inspection: Periodically inspect the air intake and exhaust vents for any obstructions. Ensure they are clear of debris, insects, or other blockages.
• Water Filter Cleaning: If your system includes an inline water filter, clean or replace it as recommended by the manufacturer to prevent sediment from entering the unit.
• Leak Checks: Regularly inspect all water and gas connections for any signs of leaks. Address any leaks immediately.

6. Troubleshooting

If you encounter issues with your Rinnai REP199iN water heater, refer to the following general troubleshooting steps. For complex problems or error codes, contact a qualified service technician.

• No Hot Water: Check if the unit has power and if the gas supply valve is open. Ensure no error codes are displayed.
• Insufficient Hot Water: Verify that the temperature setting is appropriate. Check for adequate water flow to the unit. Multiple simultaneous hot water demands might temporarily reduce temperature if the unit is undersized for peak usage.
• Error Codes: If an error code appears on the digital display (e.g., Code 63), consult the detailed troubleshooting section in the full owner's manual for specific remedies. Many codes indicate issues that require professional attention.
• Low Water Pressure: Check for closed shut-off valves, kinks in water lines, or clogged filters.

If troubleshooting steps do not resolve the issue, contact Rinnai customer support or a certified Rinnai technician.

7. Specifications

8. Warranty Information

The Rinnai REP199iN Tankless Water Heater comes with a residential guarantee:

• Heat Exchanger: 15-year warranty
• Parts: 5-year warranty
• Labor: 1-year warranty

Please refer to the official Rinnai warranty documentation for complete terms and conditions, including any exclusions or requirements for maintaining warranty coverage.

9. Support and Resources

For additional support, product guides, manuals, energy information, or to locate a qualified technician:

• Visit the official Rinnai website.
• Utilize the "Find a Rinnai PRO" tool on the Rinnai website to locate a certified installer or service professional in your area.
• Contact Rinnai customer support directly for assistance with product inquiries or technical issues.

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