We had a small fire in a heater duct hose for the duct in the upper bathroom. It was caused by the duct hose being in contact with the positive battery cable connection on the 2,000 Watt 120 volt Inverter located in the passthrough under the bathroom floor. The duct is made of foil and has a plastic liner. The plastic line is what was on fire, and the whole duct hose was hot, (the furnace was not being used at the time). Luckily we caught this before it got to be a larger fire, and also while we were sleeping. I reported this to Forest River, I haven't heard from them yet.