1. Introduction
This manual provides essential information for the safe and efficient operation, installation, and maintenance of your Rheem RTGH-90DVLP-3 Liquid Propane Condensing Tankless Water Heater. Please read all instructions carefully before installation or use.
The Rheem RTGH-90DVLP-3 is a Super High Efficiency indoor condensing liquid propane tankless gas water heater designed to deliver continuous hot water. It features Hot Start Programming to minimize cold water bursts and an Overheat Film Wrap for heat exchanger protection. Its compact, wall-mount design allows for installation in various spaces.
Figure 1: Rheem RTGH-90DVLP-3 Tankless Water Heater with Digital Display
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 is provided for the appliance.
- Do not store flammable materials near the water heater.
- Regularly inspect the unit for any signs of damage or leaks.
3. Product Overview
The RTGH-90DVLP-3 unit is designed for indoor installation and features a digital display for temperature control and status monitoring. Key components include the heat exchangers, burners, flow sensor, and control board.
Figure 2: Key Features of the Rheem RTGH-90DVLP-3
3.1. Main Components
- Digital Display: Shows current temperature and error codes.
- Control Buttons: Adjust temperature settings and access functions.
- Heat Exchangers: Primary and secondary heat exchangers for efficient water heating.
- Flow Sensor: Detects water flow to activate the heating process.
- Overheat Film Wrap: Safety feature to prevent overheating.
4. Installation
Professional installation is highly recommended for this appliance. Ensure all local codes and regulations are followed.
4.1. Pre-Installation Checklist
- Verify inlet & exhaust connection sizes and required materials.
- Confirm maximum length of vent run allowed.
- Check if the unit can deliver your required water temperature in your region.
- Ensure required installed unit clearance is met.
4.2. Mounting and Clearances
The RTGH-90DVLP-3 is a wall-mounted unit. It offers industry-leading 1/2-inch side-to-side clearance and zero front and back clearance requirements, providing flexibility for installation in compact spaces like utility closets.
Figure 3: Example Installation in a Utility Closet
4.3. Venting
As a condensing unit, the RTGH-90DVLP-3 utilizes PVC for venting, simplifying the installation process compared to non-condensing models that require stainless steel piping.
4.4. Gas and Water Connections
- A 3/4-inch natural gas line is recommended for optimal performance.
- Ensure proper inlet and outlet piping connections.
- The unit requires an electrical power connection for operation.
5. Setup
5.1. Initial Startup
After professional installation, follow the specific startup procedures outlined in the comprehensive installation manual provided with the unit. This typically involves purging air from the gas lines and checking for leaks.
5.2. Temperature Settings
The available temperature settings range from 100°F to 140°F, with a default setting of 120°F. Adjust the desired temperature using the control buttons on the unit's digital display.
6. Operating Instructions
The Rheem RTGH-90DVLP-3 provides continuous hot water on demand. When a hot water faucet is opened, the flow sensor activates the unit, and the control board determines the required heat based on inlet water temperature and flow rate. Burners ignite, and water is heated as it passes through the heat exchangers.
6.1. Hot Start Programming
This exclusive feature keeps the water heater in a ready state for 5 minutes after a faucet is turned off. This minimizes cold water bursts during back-to-back uses, such as washing dishes or taking multiple showers.
6.2. Overheat Film Wrap
The unit includes an Overheat Film Wrap for heat exchanger overheat protection. In the event of overheating, this safety feature will melt and shut down the unit to prevent damage.
6.3. How a Tankless Water Heater Works
Video 1: This video illustrates the internal workings of the Rheem RTGH-3 Condensing Tankless Water Heater, showing how water flows through the heat exchangers and how the unit adjusts to provide continuous hot water. It also highlights the Hot Start Programming feature.
6.4. Introducing Rheem Condensing RTGH Tankless Gas Water Heaters
Video 2: This video provides an overview of the Rheem Condensing RTGH Tankless Gas Water Heater series, showcasing its modern design, efficiency, and key features like LeakGuard technology and flexible installation options.
7. Maintenance
Regular maintenance is crucial for the longevity and efficiency of your tankless water heater. It is recommended to have the unit inspected and serviced annually by a qualified technician.
- Annual Inspection: A qualified technician should inspect the unit's components, including heat exchangers, burners, and venting system.
- Descaling: Depending on water hardness, periodic descaling may be required to remove mineral buildup from the heat exchanger. Consult your technician for recommended frequency.
- Clean Air Intake: Ensure the air intake is free from obstructions and debris.
8. Troubleshooting
If you experience issues with your water heater, refer to the following common problems and solutions. For complex issues or if problems persist, contact a qualified service technician.
| Problem | Possible Cause | Solution |
|---|---|---|
| No hot water | No gas supply, power outage, unit lockout, low water flow. | Check gas valve, electrical supply, reset unit, ensure adequate water flow. |
| Water not hot enough | Temperature setting too low, excessive hot water demand, mineral buildup. | Increase temperature setting, reduce simultaneous hot water use, descale unit. |
| Error code displayed | Specific internal fault. | Refer to the full manual for specific error code definitions and troubleshooting steps. |
| Water leak detected | Internal leak, loose connection. | Shut off water supply, contact a qualified technician immediately. |
9. Specifications
Below are the technical specifications for the Rheem RTGH-90DVLP-3 Liquid Propane Condensing Tankless Water Heater:
| Feature | Detail |
|---|---|
| Brand | Rheem |
| Model Number | RTGH-90DVLP-3 |
| Product Dimensions | 17.7"W x 23.7"H x 9.8"D |
| Fuel Type | Liquid Propane |
| Maximum Flow Rate | 9 Gallons Per Minute (GPM) |
| BTUs | Up to 180,000 BTUs |
| Maximum Temperature | 140 Degrees Fahrenheit |
| Efficiency | Super High Efficiency (Condensing) |
| Style | Indoor Installation |
| Mounting Type | Wall |
| Voltage | 120 Volts |
| Item Weight | 59.9 pounds |
| Special Feature | Overheat Film Wrap |
| UPC | 662021564314 |
Figure 4: Rheem RTGH-90DVLP-3 Dimensions
Figure 5: Rheem RTGH Series Performance Guide (for sizing purposes only)
10. Warranty and Support
The Rheem RTGH-90DVLP-3 is covered by the following manufacturer warranties:
- Labor: 1 year
- Heat Exchanger: 15 years
- Parts: 5 years
For warranty claims, technical support, or service inquiries, please refer to the contact information provided in your product packaging or visit the official Rheem website.
