231630 Furnace Limit Switch – Suburban SF-20 SF-25 SF-30 SF-35 RV Replacement231630 Furnace Limit Switch Suburban SF Series RV Furnace Replacement A faulty limit switch is one of the most common reasons an RV furnace shuts off unexpectedly or fails to ignite. This 231630 replacement limit switch is a direct OEM compatible fit for Suburban SF Series furnaces, restoring safe, reliable heating to your RV or camper without the need for a service call. If your furnace is cycling off prematurely or not running at all, this is the