Complete repair guide for the Rockwood/Flagstaff – Furnace Igniter & Control Board Replacement. Follow these steps to diagnose and fix the issue yourself.
Parts & Tools You’ll Need
- Suburban/Atwood RV furnace replacement unit
- Furnace igniter electrode assembly
- Furnace sail switch
- Furnace circuit board / control board
- Furnace high-limit switch
- Furnace blower motor (12V DC)
- Propane/CO combo detector alarm
- Digital multimeter (auto-ranging)
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Step-by-Step Repair Guide
Step 1: Diagnose Furnace Issues Safely
Begin by turning off your RV’s propane supply at the tank and disconnecting the negative battery terminal to ensure complete power shutdown. Use your digital multimeter to test the control board for continuity and verify the igniter electrode isn’t firing by observing for spark when the furnace attempts to ignite.
Step 2: Remove Old Furnace Assembly
Disconnect all electrical connectors from the existing furnace unit, including the blower motor and control board harnesses, then unbolt the furnace from its mounting brackets. Carefully slide the furnace out of its compartment and set it aside, taking note of all connection points for reference during reinstallation.
Step 3: Install New Control Board
Position your new circuit board in the furnace housing and secure it with the provided fasteners, ensuring it sits flush against the mounting surface. Connect all wiring harnesses according to the manufacturer’s diagram, paying special attention to the polarity of the 12V DC connections to prevent damage.
Step 4: Replace Igniter Electrode Assembly
Remove the old igniter electrode by unbolting it from the burner chamber and disconnecting its wire connector. Install the new electrode assembly in the same position, ensuring it sits at the correct gap distance from the burner (typically 3-4mm) and tighten all fasteners securely.
Step 5: Install Safety Switch Components
Mount the sail switch and high-limit switch in their designated locations on the furnace housing, using the original bracket holes for alignment. Connect both switches to the control board according to the wiring diagram, ensuring all connections are tight and properly seated.
Step 6: Reinstall Complete Furnace Unit
Carefully slide the fully assembled furnace back into the RV compartment and align all mounting brackets, then bolt it securely in place. Reconnect all propane lines to the furnace inlet, checking for leaks with soapy water, and reattach the negative battery terminal.
Step 7: Test System and Safety Features
Restore propane supply and power, then listen for the blower motor to engage and observe the igniter electrode for spark when the thermostat calls for heat. Verify that your propane/CO combo detector activates properly and use your multimeter to confirm 12V DC is reaching the blower motor and control board.
Recommended Parts
| Part | Link |
|---|---|
| Suburban/Atwood RV furnace replacement unit | View on Amazon |
| Furnace igniter electrode assembly | View on Amazon |
| Furnace sail switch | View on Amazon |
| Furnace circuit board / control board | View on Amazon |
| Furnace high-limit switch | View on Amazon |
| Furnace blower motor (12V DC) | View on Amazon |
| Propane/CO combo detector alarm | View on Amazon |
| Digital multimeter (auto-ranging) | View on Amazon |