How are 345rf tanks heated?

[ytee]

I have a 2012 345rf and was wondering how the tanks are heated? I think they are heated when the furnace runs but I have heard of other brand unit owners say their tanks are electric heated. I wanted to make sure I wasn't wasting electricity when plugged in at the house through the winter. What are the pros and cons of each way of heating tanks?
Thanks
Chris

[dalemac377]

Tanks get radiant heat off the duct work when the furnace runs. Many higher end, four season units use electrically heated tanks, not the cruisers.