Robertshaw 720-079 Gas Valve Instruction Manual

Introduction

This manual provides essential information for the safe and efficient installation, operation, and maintenance of the Robertshaw 720-079 Gas Valve. The 720 series valves are designed for intermittent pilot ignition applications in various residential heating systems. Please read these instructions thoroughly before proceeding with installation or operation.

Image: The Robertshaw 720-079 Gas Valve, showing its compact design and connection points.

Product Features

• Ignition Type: Intermittent pilot, hot surface ignition, direct spark ignition compatible.
• BTUH Capacity: 150,000.
• Valve Type: Standard opening.
• Inlet Size: 1/2 inch.
• Outlet Size: 3/4 inch.
• Compact Design: Features a compact swing radius of 3-9/16 inches for versatile OEM replacement applications.
• Integrated Components: Incorporates a manual valve, pilot valve, dual automatic valves, and a main gas pressure regulator.
• Convertible Fuel Type: Factory-set for natural gas (3.5" w.C.) and includes a regulator conversion kit for LP gas.

Safety Information

WARNING: Improper installation, adjustment, alteration, service, or maintenance can cause property damage, personal injury, or loss of life. Read these instructions thoroughly before installing or servicing this equipment.

• Installation and service must be performed by a qualified installer, service agency, or gas supplier.
• Always turn off the main gas supply before working on the valve or connected appliances.
• Check for gas leaks after installation or service using a soap solution, never an open flame.
• Ensure proper ventilation during operation.
• Do not attempt to repair the valve. Special screws are used, and replacement parts are not available to prevent unsafe repair attempts.

Setup and Installation

The Robertshaw 720-079 Gas Valve is designed for residential applications such as central heating units, space heaters, wall heaters, boilers, and mobile home furnaces. Ensure the valve is compatible with your appliance's specifications before installation.

Gas Type Conversion

The valve is factory-set for natural gas at 3.5" w.C. If converting to LP gas, use the included regulator conversion kit. Refer to the specific instructions provided with the conversion kit for proper installation. Conversion kits for different gas types are:

• Part 1751-016: To convert 720 valves to LP.
• Part 1751-018: To convert 720 valves to natural gas.
• Part 1751-019: To convert 720 step opening valves to LP.

Physical Installation

1. Ensure the main gas supply is off.
2. Mount the valve securely in the appliance, ensuring the compact swing radius is accommodated.
3. Connect the 1/2" NPT inlet and 3/4" NPT outlet to the gas lines. Use appropriate pipe sealant.
4. Make all necessary wiring connections. The wiring connections, manual selector, and adjustments are readily accessible on top of the control.
5. After installation, slowly turn on the main gas supply and check all connections for leaks using a non-corrosive leak detection solution.

Operating Instructions

The Robertshaw 720-079 Gas Valve operates in conjunction with your appliance's ignition system. The manual selector on top of the control allows for specific operational modes.

1. Initial Startup: Follow the appliance manufacturer's instructions for initial startup. This typically involves purging air from the gas lines and initiating the ignition sequence.
2. Manual Selector: The manual selector allows you to turn the gas supply to the main burner ON or OFF, and to the PILOT. Ensure the selector is in the correct position for desired operation (e.g., PILOT for lighting the pilot, ON for normal operation).
3. Pilot Lighting: If your system uses a standing pilot, follow the appliance's instructions for lighting the pilot. The valve's pilot valve controls gas flow to the pilot burner.
4. Automatic Operation: Once the pilot is established (if applicable) and the manual selector is in the ON position, the dual automatic valves will open and close based on the thermostat's call for heat.

Maintenance

Regular maintenance of your heating system, including the gas valve, is crucial for safe and efficient operation. This valve is designed for reliability and does not require user-level internal maintenance.

• Annual Inspection: Have a qualified service technician inspect the gas valve and entire heating system annually. This includes checking for proper gas pressure, leak integrity, and overall operational safety.
• Cleaning: Keep the exterior of the valve clean and free from dust or debris. Do not use harsh chemicals.
• No User Serviceable Parts: The Robertshaw 720-079 Gas Valve contains no user-serviceable parts. Do not attempt to disassemble or repair the valve. Special screws are used to prevent unauthorized access, and replacement internal components are not available. Any attempt to repair the valve internally may compromise its safety and void any applicable warranties.

Troubleshooting

If you experience issues with your heating system, consult your appliance's instruction manual first. For problems specifically related to the gas valve, consider the following:

• No Gas Flow:
  • Ensure the main gas supply to the appliance is open.
  • Check that the manual selector on the gas valve is in the correct position (e.g., ON or PILOT).
  • Verify that other gas appliances in the home are functioning, indicating a general gas supply.
• Pilot Light Not Lighting/Staying Lit:
  • Follow the appliance's pilot lighting procedure carefully.
  • Check for drafts that might be extinguishing the pilot.
  • Ensure the pilot orifice is clean and not obstructed.
• Main Burner Not Igniting:
  • Confirm the pilot light is lit and strong (if applicable).
  • Check the thermostat setting and ensure it is calling for heat.
  • Listen for the igniter spark or glow. If no ignition, the issue may be with the igniter or control board, not necessarily the gas valve itself.
• Gas Odor:
  • IMMEDIATELY turn off the main gas supply.
  • Open windows and doors for ventilation.
  • Do not operate electrical switches or phones.
  • Evacuate the premises and call your gas supplier or fire department from a safe location.

For any persistent issues or if you are unsure, contact a qualified service technician.

Specifications

Warranty and Support

For warranty information and technical support, please refer to the documentation provided with your specific appliance or contact Robertshaw directly through their official website. As the gas valve is often an integral component of a larger system, warranty terms may be subject to the appliance manufacturer's policies.

Robertshaw Official Website: www.robertshaw.com