Newmar Bay Star Sport – Furnace Igniter & Control Board Replacement

Newmar doesn’t publish a troubleshooting flowchart for furnace failures, and dealer service advisors rarely volunteer that most no-heat situations in a Bay Star Sport come down to two specific, owner-replaceable parts. You won’t find this in the owner’s manual either — what you get is a schematic diagram and a parts list, but no step-by-step on which component to suspect first or how to rule out the other one. When you’re full-timing and the furnace quits mid-season, downtime costs money, and waiting for a service appointment costs comfort. The reality is straightforward: a failed igniter electrode or a defective control board handles most of these callouts — and both are accessible to anyone with a basic socket set and the willingness to spend an afternoon in the furnace compartment. This post covers exactly what I found when I dug into ours, how I confirmed which part was actually bad, and the step-by-step to swap them out without a dealer’s markup or a multi-week service queue.

The Igniter That Actually Fires When Everything Else Tests Fine

The igniter is the first thing that fails on a Suburban SF-series furnace, and it’s the hardest to diagnose because you can have 12V at the control board, gas flow confirmed, and a blower that runs — but the furnace still won’t light. A dead electrode is invisible until you pull it out and see the ceramic cracked or the wire corroded.

What works

• Drop-in fit for SF-35, SF-42, and SF-35Q models — you won’t spend an hour figuring out if this is the right part once you pull the old one out.
• The electrode wire assembly is pre-gapped and ready to seat; you’re not hunting for the exact spacing or crimping new connectors in a cramped furnace compartment.
• Furnace fires on first try after installation — no guessing whether you need to adjust air shutter or second-guess the control board.

What doesn’t

• You have to pull the furnace shroud and access panel to confirm the old igniter is actually the problem — there’s no shortcut diagnosis without seeing the electrode itself.
• Aftermarket versions sometimes have slightly looser connector tolerances than OEM, which means you may need to crimp the spade terminals tighter to avoid intermittent no-fire conditions.

I ordered this part convinced it was the control board causing the trouble, and had the igniter half-installed before I realized the ceramic was visibly fractured — the board was innocent the whole time. 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)

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