Hole in oil hot water heater

[newhomeguy11]

I recently replaced my 2 year old 50 gallon oil hot water heater (switched over to gas). I told the installers to leave my hot water heater since it's almost brand new and I figured I could sell it. When looking at it today, I noticed a strange hole in the side (see pictures). Does anyone know what this is? Not sure if it's always been there, or if it's something the installers damaged when replacing it. Any help would be appreciated. Thanks!

 

[Dana]

It looks like a hole where a sheet metal screw had been use to hold something, but it's almost certainly not important. It's not clear if it was manufactured that way, or a hole that got put in later. The outer sheet metal skin of the water heater is just protecting the insulation- it can be really dinged up and still work just fine. Overall the water heater looks shiny and near-new, and that hole shouldn't affect resale value.