I know my unit does not have tank heaters. I felt that having the plumbing come up through the heater duct served the purpose of hatung the tanks in cold weather. I talked with John at Dynamax and he confirmed this. See my other post about hot island for a picture.
If you don't have a switch you dobt have the pads. I am on OK. I discovered my fresh water tank had dropped. It has a smapp piece of osb plywooh holding it up. Per the factory rep it is supposed to have a full sheet. Still not good enough for me. I am going to repair mine myself the way I want it repaired with LOTS of insulation. I will documet the imptovement and poat it here. It may takeca while as I am going to add tank heaters also.