Check Electrical Sockets. Sockets are easy ways for heat to escape your home, especially if they are cracked. Take off the electrical plate and reseal the inside with caulk to make sure no heat is escaping to the outside.
Ceiling fans can be used to push warm air down if you reverse the spin of the blades. Run the blades clockwise on low for maximum efficiency.
Chimneys and fireplaces, if not properly sealed, can allow cold air in and warm air out. You can help stop that leakage by putting in a new, rubber-sealed damper. If your fireplace does not have any kind of glass door or cover to seal it off, it would pay to invest in one.
If you have carpeting in furnace compartment, consider removing it and replacing it with a fireproof material. Some furnaces in manufactured homes have a wire mesh in front to prevent storage on top of the furnace; if yours is missing it is suggested to replace it as a safety measure.
Disposable furnace filters should be replaced regularly. Maintain permanent filters by removing them to wash, brush or vacuum them. Also, remove the cover of the thermostat and vacuum away dust and dirt. Take a look at the V-belt and pulleys for wear. If the belt moves more than an inch when you push it, tighten it, and be sure to check air intake too.
Make sure the area around your furnace is clean. Remove out any debris in the furnace area and prevent small amounts of dirt, dust, clothing, etc. from accumulating. Never use your furnace closet for storage or drying clothes because that can be a fire hazard.
Check interior and exterior of your doors for wear, tear, cracking or fading. Look for signs of leaking around both the sill and threshold. Check that weather stripping and seals are intact. Vinyl Weatherseal is suggested to seal any leaks around the frame and you can get it for only a few dollars!
If you live in a region with a colder climate, make sure your doors can handle the winter season. Consider investing in new doors that offer a folded steel edge sealed with double weather stripping to protect against air, pght and water penetration and insulation that is energy efficient. Combination doors come complete with a self-storing storm door and are pre-hung, pre-squared and pre-punched for fast and easy installation.