What you
MAY have there is an add-on heating element (Hott Rod ?), replaced the normal drain plug, and should have a switch to turn it on/off somewhere. Just where is/was up to whomever installed it. These are low wattage elements so wonโt affect overall current draw that much. These elements are good for normal hot water usage, but as they are low wattage, takes a bit to warm the water to the set temperature. In which case you can have both the electric element on AND use the gas option at the same time.
As far as winterizing the wh you should be able to removed the element to drain the tank. Just make sure the power is off to the element.And of course, make sure there is water in the tank before turning it on.
Tom Wilds
Blythewood, SC
2016 Newmar Baystar Sport 3004
2015 Jeep Wrangler 2dr HT