I cursed Suburban every day on this past holiday weekend where it never got more than 45 degrees in the Adirondacks of New York State and the water heater didn't work.
On the last day it hit me that when turned on the water heater would run for 10 minutes and I had no hot water. I thought about it, looked, and once I turned the third valve, the crossover valve, on the bypass system, it worked fine.
Sorry Suburban. Duhhhh
I went through 40# of Propane as it was using the furnace for 5 days and nights so I guess I saved a little gas taking cold showers.
2012 F150 F/X 4, 6cyl EcoBoost with Max tow pkg
2013 Rockwood 8280WS 5th wheel
2006 Sunline T1950
2004 T@B T-16