Robertshaw DS845 Ignition Control Module Instruction Manual

1. Overview

The Robertshaw DS845 is an ignition control module designed for specific heating applications, typically found in gas fireplaces or similar systems. This module is responsible for managing the ignition sequence, ensuring safe and reliable operation of the appliance. It operates on a 24VAC input and controls the spark gap and valve load to initiate and maintain combustion.

Important Note: This device is NOT FIELD REPAIRABLE. Any malfunction requires replacement of the entire module. Attempting to repair the unit may result in damage, injury, or fire hazard.

Figure 1: The Robertshaw DS845 Ignition Control Module. This image displays the top view of the module, showing the terminal block for wiring connections, the model number 'DS 845', and various electrical specifications printed on its label.

2. Safety Information

• Installation and servicing must be performed by a qualified installer, service agency, or gas supplier.
• Disconnect all electrical power to the appliance before installing or servicing this control module.
• Read all instructions carefully before proceeding with installation or operation. Failure to follow instructions can result in property damage, personal injury, or death.
• Ensure all wiring connections comply with local codes and ordinances.
• Do not use this device if any part has been submerged in water. Contact a qualified service technician to inspect and replace any part of the control system that has been submerged.
• This module is designed for specific applications. Verify compatibility with your appliance before installation.

3. Setup and Installation

Installation of the Robertshaw DS845 module requires careful attention to wiring and safety procedures. It is recommended that installation be performed by a qualified technician.

1. Power Disconnection: Before beginning any work, ensure that the main power supply to the appliance is completely disconnected.
2. Access: Gain access to the existing ignition control module within your appliance.
3. Labeling Wires: Carefully label all wires connected to the old module before disconnecting them. This will ensure correct re-connection to the new DS845 module.
4. Removal: Disconnect all wires and remove the old module.
5. Mounting: Mount the new Robertshaw DS845 module in the same location and orientation as the old module.
6. Wiring Connections: Connect the labeled wires to the corresponding terminals on the DS845 module. Refer to the wiring diagram provided with your appliance for specific connections. The module features terminals for INPUT (24VAC), VALVE, and SPARK GAP connections. Ensure secure connections to prevent intermittent operation.
7. Spark Gap: Verify the spark gap setting for your igniter, which should be approximately 5/64 inches as specified for this module.
8. Power Reconnection: Once all connections are secure and verified, restore power to the appliance.
9. Test Operation: Follow the appliance manufacturer's instructions to test the ignition system.

4. Operating Instructions

The Robertshaw DS845 ignition control module operates automatically in conjunction with your appliance's control system. Once installed and powered, it will manage the ignition sequence as follows:

• When a call for heat is initiated by the thermostat or appliance control, the DS845 receives a 24VAC signal.
• The module then sends power to the gas valve and simultaneously generates a high-voltage spark across the igniter electrodes.
• Upon successful ignition of the main burner, the module senses the flame and discontinues the spark.
• The module continues to monitor the flame during the heating cycle. If the flame is lost, the module will attempt re-ignition or shut down the gas supply for safety.

Refer to your appliance's user manual for specific instructions on how to operate your heating system.

5. Maintenance

The Robertshaw DS845 ignition control module is a sealed unit and is NOT FIELD REPAIRABLE. No user maintenance is required for the module itself.

For optimal performance of your heating appliance, it is recommended to:

• Have your appliance inspected and serviced annually by a qualified technician.
• Ensure the area around the module and appliance is kept clean and free from dust or debris.
• Periodically check for any loose wiring connections, ensuring power is disconnected before inspection.

6. Troubleshooting

If your appliance is experiencing issues, consider the following common troubleshooting steps. Always ensure power is disconnected before inspecting components.

• Appliance Not Igniting:
  • Check if the main power supply to the appliance is on.
  • Verify that the gas supply to the appliance is open.
  • Inspect all wiring connections to the DS845 module and ensure they are secure.
  • Check the igniter electrodes for proper spacing (5/64 inch) and cleanliness.
  • If the module is buzzing loudly or making unusual noises, it may indicate an internal fault.
• Appliance Ignites but Shuts Off Quickly:
  • This often indicates a problem with flame sensing. Ensure the flame sensor is clean and properly positioned in the flame path.
  • Verify proper grounding of the appliance and control system.
• Intermittent Operation:
  • Check for loose wiring connections or corrosion on terminals.
  • Ensure stable 24VAC power supply to the module.

If troubleshooting steps do not resolve the issue, and you suspect the DS845 module is faulty, it must be replaced by a qualified technician. As stated, the module is not field repairable.

7. Specifications

8. Warranty and Support

Specific warranty information for the Robertshaw DS845 module is typically provided by the manufacturer or the seller at the time of purchase. Please refer to your purchase documentation for details regarding warranty coverage.

For technical support or further assistance, please contact Robertshaw customer service or consult their official website. When contacting support, have your model number (DS845) and part number (780-502) readily available.