The 16000btu furnace works fine in our 20-year-old Pup. But I wish it drew less current when boondocking with solar panel (& Group 24 Marine battery). This model has been around a long time...reliably in many RVs. So...I'm wondering if anyone has retrofit a more efficient fan/motor, etc. Ideas also welcome for replacing function of the really-hard-to-move ON/OFF slider on bottom of thermostat.