Here is a link to Dutchmans archived literature
for years late 80's to 2010.
On our 05' Cub we had the DSI gas / electric hot water heater. Inside the cabinet below the sink there were 3 lighted bat switches. #1 water pump, #2 water heater (gas), #3 water heater (electric).
Here is the PDF link to the 2002 Cub brochure
Here it shows there was an option for DSI water heater. I wonder for 02' the DSI option for a DSI (Direct Spark Ignition) was just a gas only water heater, where the standard water heater would have been just a manual lighting water heater. For 05' the option was worded Gas / electric DSI water heater