Complete repair guide for the Newmar Bay Star Sport – Furnace Igniter & Control Board Replacement. Follow these steps to diagnose and fix the issue yourself.
Parts & Tools You’ll Need
- Suburban RP-35Q 35,000 BTU/h RV Replacement Core for Suburban Furnace Series SF-35, SF-35Q, SF-42, SF-42Q, and SF-Q (2609A) — Suburban/Atwood RV furnace (replacement unit)
- Fit For Suburban RV Furnace Parts 232286,Single Probe Gas Furnace Igniters Electrode with Wire Assembly, Camper Furnace For Suburban 232286 Above 934701426 SF-20, SF-25, SF-30, SF-35 (SF Series) — Furnace igniter electrode
- DTAIR 33082 Sail Switch Replacement for Select Dometic Atwood RV Furnace(Pack of 2) — Furnace sail switch
- 520814 Rv Water Heater Module Board Ignition Control Circuit Board Compatible with Suburban Furnace SW4D, SW6D, SW6DE, SW12D, SW6DEM RV Water Heaters,Replace 520814 520820 520871 33550L (With lid) — Furnace circuit board / control board
- DTAIR 33082 Sail Switch Replacement for Select Dometic Atwood RV Furnace(Pack of 2) — Furnace high-limit switch
- Suburban 232684 RV Furnace 12v SF-Series DC Blower Motor, SF-35, SF-35F, SVF-35, SF-42, SF-42F OEM Caliber — Furnace blower motor (12V DC)
- RV Carbon Monoxide & Propane Gas Alarm, Briidea Dual LP/CO Detector with Separate LED Indicator Light, 100dB Loud Alarm, 12 VDC, Black — Propane/CO combo detector alarm
- FKM Pro Digital Multimeter Tester TRMS 6000 Counts,Smart Rechargeable Voltmeter 5″Color LCD,Auto-Ranging Automotive Multimeters,for AC/DC Current/Voltage,NCV,Ohm,Capacitance,Resistance,Continuity,Temp — Digital multimeter
Step 1: Diagnose Furnace Ignition Failure
Start by identifying whether your furnace won’t ignite at all or ignites intermittently. Use your digital multimeter to test for 12V DC power at the control board connector—if you’re getting voltage but no spark at the igniter electrode, the igniter itself is likely faulty. If there’s no power reaching the board, check your RV’s 12V system and battery connections before proceeding with component replacement.
Step 2: Shut Down Systems and Isolate Power
Turn off the furnace at your RV’s thermostat and switch the propane supply valve to the OFF position. Locate your RV’s main 12V battery disconnect switch and turn it off to eliminate all electrical power to the furnace control board. Wait at least 5 minutes to ensure any residual capacitor charge dissipates before touching any electrical components.
Step 3: Access Furnace and Remove Control Board
Remove the furnace access panel by unbolting the securing clips—typically 2-3 quarter-inch bolts on your Bay Star Sport model. Carefully photograph the wire harness connections to the control board using your phone for reference during reassembly. Gently disconnect all wire connectors from the board by pressing the release tabs, then unbolt the board itself from the furnace mounting bracket and set it aside.
Step 4: Replace Igniter Electrode Assembly
Locate the igniter electrode mounted near the furnace burner tube, typically held by a single bolt or snap clip. Remove the electrode carefully and inspect the surrounding ignition cavity for any soot or debris buildup—clean with a dry cloth if needed. Install the new furnace igniter electrode by reversing the removal process, ensuring the electrode sits approximately 1/8 inch from the burner opening for proper spark gap.
Step 5: Install Replacement Control Board
Position your new furnace circuit board into the mounting bracket and secure it with bolts, tightening to a snug fit without over-torquing. Reconnect all wire harnesses to the board terminals, matching the connector positions to your reference photos—ensure each connector clicks fully into place. Double-check that the sail switch connector and high-limit switch wiring are properly seated, as loose connections are a common cause of intermittent ignition issues.
Step 6: Verify All Connections and Reassemble
Conduct a visual inspection of every connection point, looking for pinched wires, corroded terminals, or loose connectors that could cause future failures. Reinstall the furnace access panel and secure all bolts firmly. Check that the propane supply line connections are tight and show no signs of leaks by applying a soapy water solution—bubbles indicate a leak requiring immediate attention.
Step 7: Test Furnace Operation and Monitor Performance
Restore 12V power by flipping your battery disconnect switch back on, then switch your thermostat to heating mode at 75°F. Listen for the ignition spark at the electrode (you should hear a clicking sound) followed by the blower motor engaging within 3-5 seconds of the thermostat calling for heat. Allow the furnace to run for 15 minutes while monitoring that your propane/CO combo detector shows no alarms, then confirm warm air is flowing from the vents at normal temperature.