We just got our 27DSRL a couple of weeks ago and yes, regarding that 3rd switch at the console, that is the "Dump Station" Amber light on the driver side by the Black/Grey Tanks. I'm trying to figure out the hot water switches now. Different post though, I will not "hijack" this one for that question. Happy Trails to you!
Ed, Christy and Johnny (our Halo Rescue 1/2 Lab and 1/2 Aussie)
TV='05 Chevy Silverado 1500 Longbed with Towing Package
TT='15 Jayco White Hawk 27DSRL