You don't need to be a do-it-yourselfer to enjoy the satisfaction that goes with keeping your home in smooth working condition. Even when you assign professionals to preventive maintenance procedures for example, when getting your heating system ready for a snug winter there are details that you can take care of yourself. The furnace or oil-burner expert, unless you've reported specific problems, may only concentrate on the heat-generating equipment and ignore the distribution system. So, the homeowner with optimum HouseMastery skills will get into the habit of regularly cleaning all registers and duct openings.
If you have a hot-water system, you may have to "bleed" each baseboard section or radiator. This entails opening each bleeder valve a quarter-turn or so, while the system is hot, and leaving it open until air stops hissing and a tiny stream of water sprays out. This keeps your distribution system in optimum working order.
If you have a humidifier, make sure the water compartment is cleaned regularly and mineral deposits removed. Check the absorbent media pads, which often dry out and deteriorate during the hot summer months.
To complete your inspection, check the insulation in your attic. It keeps the heat in the lower, liveable portion of your home where it belongs. Be sure your insulation has been properly installed and remains expanded. If there is no vapor barrier in your insulation, or if it has been installed with the barrier facing the attic instead of the rooms below, moisture will collect in the insulation fibers and reduce the insulating value. The insulation should be at least six-inches thick, and should fill every inch between ceiling beams.
If you find gaps, you can fill them with similar material. Be sure to use gloves and a dust mask to avoid irritation or injury. Incidentally, don't block attic vents on the theory that it will help keep your house warm on the contrary, that's the job of the insulation. And good air circulation in the attic is beneficial, even in the winter.