Originally Posted by dieselguy
I was thinking ... every once in a while they install Atwood water heaters. Do you remember if it had a plastic or metal drain plug? If it was plastic ... it is an Atwood and it'll be a 15/16" socket. The drain plug on Suburbans are actually a sacrificial rod (anode) and are metal. Atwood water heaters are aluminum, so they don't need the anode.
You can also usually do a quick glance at the water heater door latch and tell the brand difference between an Atwood and Suburban also.
The stock Suburban latch is plastic and the Atwood is metal. Bclemens taught me that. Now if the latch has been replaced, then it's not so easy.