Are you positive you want a high-E model? I installed a Lennox Pulse 21 in 1992 with the idea that I'd be saving money on propane and upkeep. The repair bill for ten years is slightly over $600 (on top of regular service calls and cleaning/inspections). The ignition control has been replaced twice (the first time on warranty). A neighbor who is replacing his furnace talked with sales persons from three brands, and all three recommended he stay away from the high-E. Too much expense up front and in repairs to ever make up for the savings in fuel.