Common causes include low suction pressure (below 55 PSI)

Time-Delay Functionality: Engineered as a slow-blow fuse to handle the initial inrush current from circulator pumps and combustion blowers

Built for efficiency in tight mechanical spaces

Whether you are performing a furnace control board repair or an HVAC 24V transformer replacement

Williams P168400 Burner L99H008 Common causes include low suctionThe Williams P168400 Burner is a precision engineered OEM replacement part specifically designed for Williams Direct Vent Wall Heaters, primarily supporting the 1403 series such as models 1403821 and 1403822. As a veteran grade burner assembly, it is constructed from high grade stainless steel to provide superior thermal resistance and maintain consistent flame stability in gravity direct vent furnaces. Experienced technicians recognize the P168400