The clearest signs your home is losing heat are rooms that never warm up, drafts you can feel near outlets and baseboards, a furnace that runs almost nonstop, and a heating bill that jumps more than the weather explains. In Iowa, frost that melts unevenly on the roof and icicles along the eaves are two more giveaways. Most of these trace back to air leaks and thin insulation in the attic, rim joists, and walls. October is the right time to look. The furnace is just starting t