1. Introduction
This manual provides essential information for the safe and efficient use of your Takagi T-H3-DV-P Indoor Tankless High Efficiency Condensing Water Heater (LP). Please read all instructions carefully before installation or operation to ensure proper function and to prevent property damage or personal injury. Keep this manual for future reference.
Figure 1: Front view of the Takagi T-H3-DV-P Indoor Tankless Water Heater. This image shows the compact design, the Takagi logo, and the integrated control panel at the bottom.
2. Safety Information
Important: Failure to follow these safety instructions could result in fire, explosion, electric shock, property damage, personal injury, or death. Installation and service must be performed by a qualified installer, service agency, or gas supplier.
- Ensure proper ventilation as specified in the installation instructions.
- Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.
- If you smell gas:
- Do not try to light any appliance.
- Do not touch any electrical switch; do not use any phone in your building.
- Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions.
- If you cannot reach your gas supplier, call the fire department.
- This appliance is for indoor use only.
- Always disconnect power before servicing the unit.
3. Product Features
The Takagi T-H3-DV-P is an advanced tankless water heater designed for high efficiency and durability. Key features include:
- Ultra-Low NOx Condensing Technology: Provides significant energy cost savings and meets stringent emission standards.
- High Efficiency: ENERGY STAR qualified with a 0.93 energy factor.
- Durable Heat Exchangers: Features a commercial-grade HRS35 copper primary heat exchanger and a Type 316L stainless steel secondary heat exchanger for extended lifespan.
- Electronic Ignition: Eliminates the need for a pilot light, enhancing safety and efficiency.
- Built-in Temperature Controller and Diagnostics: Allows for precise temperature setting and easy troubleshooting.
- Internal Freeze Protection System: Protects the unit in cold environments.
- Power Direct Vent Design: Offers flexible venting options using PVC, CPVC, or ABS piping.
- Multi-Link Capability: Can be easy-linked up to 4 units without additional parts, and multi-linked up to 20 units for larger commercial applications.
- LP Gas Compatibility: Designed for use with Liquid Propane (LP) gas.
4. Setup & Installation
Installation of the T-H3-DV-P unit must be performed by a qualified professional in accordance with all local and national codes and regulations. This section provides a general overview; refer to the detailed installation guide provided with the product for complete instructions.
4.1 Pre-Installation Checklist
- Verify that the unit is the correct model (T-H3-DV-P) and fuel type (LP) for your application.
- Ensure adequate clearance around the unit for service and ventilation.
- Confirm availability of appropriate gas supply, water supply, and electrical connections.
- Prepare venting materials (PVC, CPVC, or ABS) according to local codes and manufacturer specifications.
4.2 Mounting the Unit
The T-H3-DV-P is designed for wall or ceiling mounting. Use appropriate mounting hardware capable of supporting the unit's weight (approximately 62 pounds) when filled with water. Ensure the mounting surface is structurally sound.
4.3 Plumbing Connections
- Connect cold water inlet and hot water outlet lines.
- Install isolation valves and a pressure relief valve as required by code.
- Flush the water lines thoroughly before connecting to the unit to remove debris.
4.4 Gas Connections
Connect the LP gas supply line to the unit's gas inlet. Ensure all gas connections are properly sealed and tested for leaks using a non-corrosive leak detection solution.
4.5 Electrical Connections
The indoor model includes a factory-installed power cord. Connect the unit to a properly grounded electrical outlet as per local electrical codes. Verify the correct voltage and amperage requirements.
4.6 Venting
Install the power direct vent system using approved PVC, CPVC, or ABS materials. Follow the manufacturer's guidelines for vent pipe sizing, length, and termination to ensure proper combustion and exhaust.
5. Operating Instructions
Once installed and all connections are verified, the T-H3-DV-P is ready for operation. The unit features a built-in temperature controller for user adjustments.
5.1 Initial Startup
- Ensure all water and gas supply valves are open.
- Open a hot water faucet in your home to allow water to flow through the unit. This purges air from the system.
- Plug in the power cord or turn on the electrical supply to the unit.
- The unit will perform a self-diagnostic check and then ignite to heat the water.
- Close the hot water faucet once hot water is consistently flowing.
5.2 Setting Water Temperature
Use the control panel on the front of the unit to adjust the desired hot water temperature. Refer to the display for current settings and error codes.
- Press the UP or DOWN arrows to increase or decrease the temperature.
- The display will show the set temperature.
- Allow a few moments for the unit to adjust to the new setting.
5.3 Normal Operation
The unit will automatically activate when a hot water faucet is opened and deactivate when it is closed. The flow rate and incoming water temperature will influence the maximum achievable hot water temperature.
6. Maintenance
Regular maintenance ensures optimal performance and longevity of your tankless water heater. It is recommended that a qualified service technician perform annual maintenance.
6.1 Descaling the Heat Exchanger
Mineral deposits (scale) can build up in the heat exchanger, reducing efficiency. Descaling should be performed annually or more frequently in areas with hard water.
- Turn off the power and close the gas and water supply valves to the unit.
- Connect a descaling pump and hoses to the service valves (if installed).
- Circulate an approved descaling solution through the unit for the recommended duration.
- Flush the unit thoroughly with fresh water after descaling.
- Restore water, gas, and power supplies.
6.2 Inspecting the Vent System
Periodically inspect the vent pipes for any obstructions, leaks, or damage. Ensure all connections are secure.
6.3 Cleaning the Water Inlet Filter
The water inlet filter should be checked and cleaned periodically to prevent debris from entering the unit.
- Turn off power and water supply.
- Locate and remove the water inlet filter.
- Rinse the filter under running water to remove any sediment.
- Reinstall the filter and restore water and power.
7. Troubleshooting
This section provides solutions for common issues. For complex problems or if an error code persists, contact a qualified service technician.
| Problem | Possible Cause | Solution |
|---|---|---|
| No hot water / Unit not igniting |
|
|
| Inconsistent hot water temperature |
|
|
| Error code displayed | Specific system malfunction | Refer to the detailed error code list in the full installation manual or contact customer support. |
8. Specifications
Technical specifications for the Takagi T-H3-DV-P Indoor Tankless Water Heater:
- Model: T-H3-DV-P
- Fuel Type: Liquid Propane (LP)
- Mounting Type: Wall or Ceiling
- Efficiency: 0.93 Energy Factor (ENERGY STAR Qualified)
- Maximum Flow Rate: 10.0 Gallons Per Minute (GPM)
- Heat Exchanger: HRS35 Commercial-Grade Copper (Primary), Type 316L Stainless Steel (Secondary)
- Ignition: Electronic
- NOx Emissions: Ultra-Low NOx Condensing Technology
- Vent Type: Power Direct Vent (PVC, CPVC, ABS)
- Weight: Approximately 62 pounds
- Dimensions: Approximately 34 x 23 x 11 inches (Package Dimensions)
- Special Features: Internal Freeze Protection System, Built-in Temperature Controller and Diagnostics, Easy-Link up to 4 units, Multi-Link up to 20 units.
9. Warranty & Support
For detailed warranty information, please refer to the warranty card included with your product or visit the official Takagi website. Keep your proof of purchase for warranty claims.
For technical support, service, or to locate an authorized service provider, please contact Takagi customer service. Contact information can typically be found on the manufacturer's website or in the product packaging.
