WINNEBAGO MICRO MINNIE 1700BH - Furnace Igniter Replacement

WINNEBAGO MICRO MINNIE 1700BH – Furnace Igniter Replacement

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Complete repair guide for the WINNEBAGO MICRO MINNIE 1700BH – Furnace Igniter Replacement.

Parts & Tools You’ll Need

Step 1: Diagnose Furnace Ignition System Failure

Start by turning on your furnace and listening for the characteristic spark clicking sound—if you hear nothing or the furnace won’t ignite after 10 seconds, your igniter system has failed. Locate your furnace compartment (typically accessed from an exterior sidewall panel on the Micro Minnie) and visually inspect the spark electrode for cracks, corrosion, or heavy carbon buildup. Check your thermostat display for fault codes; the Atwood 8531-IV board may flash error codes indicating ignition failure. Before proceeding, turn off all power to the furnace at the main breaker and allow 5 minutes for residual power to dissipate to ensure your safety.

Step 2: Remove Furnace Access Panel and Components

Using a Phillips or socket wrench (typically 7/32-inch), remove the four to six bolts securing the furnace access panel and carefully set it aside, noting the orientation of any gasket material. Disconnect the wire harness from the old control board by gently twisting and pulling each connector tab downward—do not yank on the wires themselves. If your furnace has the older Suburban NT-16 / SF-30 Control Board, you’ll need to note which wires connect to which terminals by taking a photo before disconnection. Take care not to bend or stress the delicate wiring, as these connections are critical to proper ignition sequencing.

Step 3: Replace Furnace Igniter Control Board Assembly

Remove the old control board by unbolting it from its mounting bracket using a 7/32-inch wrench, typically requiring 8-12 inch-pounds of torque for removal. Position your new Atwood 8531-IV Furnace Control Board in the exact same location and orientation, aligning the bolt holes carefully before hand-tightening all fasteners. Once aligned, torque each bolt to 10 inch-pounds in a cross-pattern to ensure even pressure and prevent board warping. Reconnect the wire harness to the new board, matching each connector to the terminal diagram on the board’s label—incorrect connections will prevent ignition.

Step 4: Install New Spark Ignitor Electrode and Wire

Locate the spark electrode assembly, typically positioned near the burner box entrance, and disconnect the old electrode by twisting the connector cap counterclockwise and pulling straight out. Remove the mounting bolt (usually 1/4-inch) securing the old electrode bracket, noting any ceramic or fiberglass insulation that must be preserved on the new unit. Install the new Spark Ignitor Electrode + Wire assembly by sliding it into the burner box opening at a 45-degree angle, ensuring the ceramic tip is positioned 1/8-inch from the ignition target surface. Secure the mounting bolt to 12-15 inch-pounds of torque and reconnect the wire harness, making sure the connection is hand-tight and fully seated.

Step 5: Replace Furnace Sail Switch Safety Component

The sail switch detects proper airflow and prevents furnace operation if the blower fails; locate it near the furnace air intake on the Micro Minnie. Disconnect the two-wire harness from the old switch by pinching the retention clip and pulling gently, then unbolt the switch housing using a 5/16-inch wrench. Install the new Furnace Sail Switch Replacement by aligning the switch body with the airflow path and tightening the mounting bolt to 8-10 inch-pounds—do not overtighten, as this can crack the plastic housing. Reconnect the two wires to the new switch, ensuring they snap fully into the connector until you hear a distinct click indicating a secure connection.

Step 6: Reinstall Access Panel and Verify Seals

Before closing the furnace compartment, inspect the rubber gasket around the access panel for cracks, tears, or permanent deformation; replace if the seal appears compromised. Position the access panel carefully and thread all four to six bolts by hand first, then torque each bolt in a star pattern to 12-15 inch-pounds to ensure an airtight seal. Check that all wire harnesses are routed away from the burner box and not pinched between the panel and frame. Secure any loose wiring with adhesive-backed clips, ensuring no wires contact hot surfaces once the furnace operates.

Step 7: Test Furnace Ignition and Monitor Performance

Restore power to the furnace at the main breaker and set your thermostat to 5 degrees above the current interior temperature to trigger a heating cycle. Listen carefully for the spark igniter clicking for 5-8 seconds, followed by a soft “whoosh” as the burner ignites and the blower motor engages within 30 seconds of flame detection. Observe the flame visibly through any inspection window (if equipped) to verify it’s steady and blue, not orange or yellow, which would indicate a dirty burner. Allow the furnace to run for 15 minutes, checking that hot air flows from the vents and the thermostat cycles normally; if ignition fails or the furnace shuts down prematurely, power down immediately and recheck all wire connections.