Gas Water Heater Thermostat Instruction Manual

1. Product Overview

This manual provides essential information for the installation, operation, and maintenance of the ETHEDTJ Gas Water Heater Thermostat, designed as a universal replacement for Robertshaw 110 Series Water Heating Gas Valves. This thermostat is crucial for regulating water temperature and ensuring safe operation of your gas water heater.

Figure 1: Robertshaw 110-202 Gas Water Heater Thermostat. This image displays the Robertshaw 110-202 gas water heater thermostat. Visible components include the main gas valve body, the black pilot knob labeled 'PILOT ONE', and a grey knob for temperature or main burner pressure adjustment. A label on the side indicates 'ROBERTSHAW 76-037-013 220RTSP' and states 'ASSEMBLED IN USA'. The copper sensing tube extends from the right side of the unit.

2. Key Features

• Universal Replacement: Designed for compatibility with Robertshaw 110 Series Water Heating Gas Valves.
• Integrated ECO System: Features a built-in, non-cycling Energy Cut-Off (ECO) system for enhanced safety.
• Over-Temperature Protection: The ECO system automatically shuts off all gas to the water heater in the event of excessive water temperatures.
• Safety Mechanism: Once the ECO system is activated (opened), the control will not function and requires replacement for continued safe operation.
• Specific Part Numbers: Compatible with part number 110-202 and factory part number 220RTSP.

3. Safety Information

WARNING: Installation and service of this gas water heater thermostat must be performed by a qualified installer, service agency, or gas supplier. Failure to follow these instructions could result in fire or explosion, causing property damage, personal injury, or loss of life.

• Always shut off the gas supply to the water heater before beginning any installation or maintenance.
• Ensure proper ventilation during installation and operation.
• Check for gas leaks after installation using a non-corrosive leak detection solution.
• Do not attempt to bypass or reset the Energy Cut-Off (ECO) system once it has been activated. The unit must be replaced.
• Refer to your water heater's specific manual for additional safety guidelines.

4. Installation and Setup

This thermostat is designed for replacement applications. Due to the nature of gas appliances, it is strongly recommended that installation be performed by a certified professional. The following general steps are provided for informational purposes only and do not substitute professional guidance.

1. Preparation: Turn off the gas supply to the water heater at the main shut-off valve. Turn off the water supply and drain the water heater tank.
2. Removal of Old Thermostat: Carefully disconnect the gas lines and remove the old thermostat from the water heater. Note the orientation and connections.
3. Installation of New Thermostat: Install the new ETHEDTJ thermostat, ensuring all connections are secure and properly sealed. The thermostat features a 1/2" Inverted Flare Outlet and a 1/2" Pipe Inlet.
4. Sensing Tube Insertion: Insert the 5-1/2" sensing tube into the designated port on the water heater.
5. Gas Line Connection: Reconnect the gas lines. Ensure the 1-1/2" Inverted Flare x 3/8" Pipe Adapter is used if necessary.
6. Leak Check: After installation, turn on the gas supply slowly and check all connections for leaks using a suitable leak detection solution. Do not use an open flame.
7. Water Supply: Refill the water heater tank before igniting the pilot.

5. Operation

Once installed and checked for leaks, the thermostat controls the water heater's operation.

• Pilot Ignition: Follow your water heater's specific instructions for igniting the pilot light. The thermostat has a pilot knob (labeled "PILOT ONE" as seen in Figure 1).
• Temperature Setting: Adjust the temperature knob to your desired water temperature. The factory setting for this thermostat is 160°F (71°C).
• Automatic Regulation: The thermostat will automatically regulate the gas flow to the main burner to maintain the set water temperature.
• Energy Cut-Off (ECO): In the event of an over-temperature condition, the built-in ECO system will activate, shutting off the gas supply. If this occurs, the thermostat must be replaced.

6. Maintenance

Regular maintenance of your water heater system, including the thermostat, is essential for safe and efficient operation.

• Annual Inspection: It is recommended to have your water heater and its components, including the thermostat, inspected annually by a qualified technician.
• Cleanliness: Keep the area around the water heater and thermostat clean and free from obstructions.
• Leak Checks: Periodically check gas connections for leaks using a non-corrosive leak detection solution.
• No User Serviceable Parts: The thermostat itself contains no user-serviceable parts. Do not attempt to disassemble or repair the unit.

7. Troubleshooting

If you experience issues with your water heater's temperature regulation or gas supply, consider the following:

For issues not listed here or if troubleshooting steps do not resolve the problem, contact a qualified service technician.

8. Specifications

9. Warranty and Support

For warranty information or technical support regarding your ETHEDTJ Gas Water Heater Thermostat, please refer to the documentation provided with your purchase or contact the seller directly.

Important Note: As this is a safety-critical component, any issues or concerns should be addressed by a qualified professional.