How to Fix Suburban SF-42 Furnace Rumble and Backfire Issues
I looked everywhere online for answers but as a first-time RV owner, I'm completely lost why my 2003 Alpine coach's Suburban SF-42 furnace keeps rumbling and backfiring nonstop! This thing fires up fine initially, but then it starts making these awful rumbling sounds and actually backfires through the intake - scared the hell out of me the first time it happened. The worst part is it's not heating worth a damn even though it runs constantly.
I've already cleaned what I could reach and checked for obvious blockages, but I'm wondering if this could be an air-fuel mixture issue? The unit is over 20 years old now, so I'm prepared for the possibility that major components might need replacing. Could this be related to gas pressure problems, or maybe the igniter is going bad and causing delayed ignition? I really need to understand what's actually causing these rumbling and backfire symptoms so I know what to focus on next. …more
I've already cleaned what I could reach and checked for obvious blockages, but I'm wondering if this could be an air-fuel mixture issue? The unit is over 20 years old now, so I'm prepared for the possibility that major components might need replacing. Could this be related to gas pressure problems, or maybe the igniter is going bad and causing delayed ignition? I really need to understand what's actually causing these rumbling and backfire symptoms so I know what to focus on next. …more
