[RGordon]

You would think with the insulation R-Values being so high, you would be able to heat it with a 100 watt light bulb. The slides are just killers in letting in cold air and just recently I installed a new solid rubber seal under the living room/kitchen slide. Will check out the end results this winter. If the twin furnaces are not independently wired, then I would think they are not wired correctly since you have two heat sensors.