Caulk around gutter seams and downspout seams, plumbing and furnace vent pipes. Apply caulk to any seams in flashing where the roof and the siding meet. Caulk around door and window frames, the dryer vent and cable entrances. Check and replace any worn weatherstripping around doors.
Check the roof for loose or cracked seams and joints, which should be resealed every year. Repair any punctures or cracks in the roof and tighten or replace loose fasteners. Apply roof coating on a warm, dry day; brush the coating on following the manufacturer's directions.
Inspect the jacks or blocks that support the double wide mobile home.Check the mobile home to be sure it is level. Replace any loose or broken blocks to keep the mobile home from sagging. If you live in an area where the ground freezes and heaves, slightly loosen the tie-downs to avoid damage from the freezing and thawing. Re-tighten the tie-downs in the spring.
Check the skirting on the home to make sure it is secure, but still provides enough ventilation for the furnace to operate properly.
Install heat tapes on any water pipes that have could freeze. Never overlap the heat tape over itself as that can cause a fire hazard. If heat tapes have been previously installed be sure they are operating properly.
Install storm windows and storm doors. Check that the seals are in good condition to seal out drafts.
Have fireplace chimney checked and cleaned by a professional to eliminate the danger of fire from creosote build up.
Vacuum the area around the furnace. Remove anything that has been stored near it. Replace furnace filters. Never use the furnace closet for storage.
Have the furnace checked and cleaned by a professional, who should inspect the blower motor, belt, pulleys and flue assembly.