We do not own a windjammer but what comes to my mind would be the power outlet to run the fire place if it is also a heater like the one in our georgetown xl 378
Our fire place is also a heater but has a separate power circuit. They tend to draw close to 1500 watts which is the max for most circuits.
Our unit has 2 circuits, one for the TV and the other for the fireplace.
I suppose if you keep the heater down and not up all the way it would work without maybe tripping a breaker.
2013 Georgetown XL 378
2008 Honda CR-V