1. Maintain your furnace
Do-it-yourself: Check furnace filters once a month for lint buildup, and clean or replace them every three months. Clogged with dirt and dust, they can be an energy suck and won’t last as long. Regardless of age or quality, a furnace should undergo a checkup every two years (or annually, for an oil system) to prevent expensive breakdowns and maintain the manufacturer’s warranty.
Big fix: Pellet stoves heat up large spaces by burning sticks of compressed sawdust and scrap wood. They take more maintenance than gas or oil stoves but allow you to turn the thermostat down, or even off, if you’re spending a lot of time in one part of the house.