Jeremy - When we got ours, we had the same issue, so I got a leaf blower to push through the ducts, and found a nice pice of crumpled up lunch bag blocking probably 80% of the duct flow.....May be your situation is the same. My wife also had the genius idea of buying a small ceramic disc heater to use when hooked up. I think it is a Pelonis and about $90
1.) It is WAY quiet compared to the furnace.
2.) It is small, so it fits easily in any cabinet.
3.) We only use it when hooked up, but even in the sub zero temps, the furnace does not come roaring to life like the turbine on an F-18! As well, less trips for refills on the LP tanks!
Loving the Northwest!!!!
07 Tundra pulling a 2013 25BHS