Chukarhunter Posted October 29, 2022 Share Posted October 29, 2022 I too have a 2020 LE II and I definitely bought mine new as a 4 season trailer and as I use it extensively through the winter in Oregon, I do not winterize it. I am extremely pleased with the LE II overall, but OTT completely failed when they engineered the forced air heating system. A forced air heating system does not distribute hot air throughout the living space, it has return ducts that pull hot air from the supply ducts across the living space to a one or more return ducts and back to the furnace. Oliver only put in one return duct and they located it immediately in front of the furnace itself. This means that there is no circulation of heated cabin air through the basement. It is dead air space. Even more inexcusable, OTT didn't put any return vent in the bathroom so when the bathroom door is closed, the supply vent in the bathroom pressurizes the bathroom space and warm air doesn't flow into the bathroom. Given the primary problem is a lack of properly sized and located return air vents, adding or relocating supply vents will not be very effective at warming the basement. I too spent did lots of testing with thermostats to get a good understanding of basement temperatures at various cabin temperatures. Like you, I found that no matter how hot I heated the cabin, the area around the outside shower would inevitably fall to around 5 degrees above the outside temperature. I determined the main reason was the lack of heated air circulating through the basement due to the lack of appropriately located return vents in the cabin. I also found that the tiny vents in the bottom of the trailer designed to drain any water that finds its way to the basement are a problem in cold weather given the flaws in the heating system. There are enough tiny air leaks in the cabin to create a slow convection effect which draws cold outside air slowly through the basement vents. Since there is no warm air circulating through the basement even when the furnace is running given the flawed design, this slow intrusion of outside air pools in the basement creating the dramatic temperature differentials between the cabin and the basement. I have not permanently fixed the problem yet, but found a temporary workaround that I am confident is good down to 15 degrees or so. If you have the inverter like I do, there is a large street side hole just behind the battery box (to access the inverter GFCI). When it gets cold, I just unscrew and remove the cover and create a second temporary street side return vent. Now more than 50% of the hot cabin air flows into the street side of the basement and across the water tanks and rear area stirring up the air. The area by the outside shower now varies less than 10 degrees from cabin temperature and the battery box stays within 5 degrees of cabin temperature (I have lithiums and have sealed and insulated the battery door). The furnace seems to run quieter and the cabin heat is more evenly distributed. The walls don't get quite as cold either. This winter if it gets real cold, I will also temporarily tape over the vents under the trailer to stop the convection currents from pulling cold outside air directly into the basement. For me, I think the permanent fix is to add a few return vents to the trailer. I will probably put one under the front dinette next to the CO detector and another smaller one in the bathroom. This should ensure that the entire basement enjoys adequate circulation of warm air when the furnace is running and that the bathroom is warm even with the door closed. You may want to try unscrewing the cover from the street side hole in front of the inverter and see if you experience the same improvements in basement temperatures that I did. 4 5 Steve and Lornie LE II Standard Hull #657 2004 4Runner 4.7 L V8 Oregon Link to comment Share on other sites More sharing options...
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