Marley Engineered Products 4520-0011-002 Limit Switch Safety Optimized: The SPNO close
Platform notes & fabric story
Description
Marley Engineered Products 4520 0011 002 Limit Switch Safety Optimized: The SPNO close Safety Optimized: The SPNO close on fall logic prevents gas valve activation if the venting system is obstructed or the draft is insufficient The most common indicator is the "short cycling" effect where the burner ignites for several seconds and then shuts down