Check your furnace filter and replace it.
If your home has a furnace, start by turning it off, then removing the filter. The filter will be inside the furnace or return air vent. The filter itself will have an arrow that indicates the direction of airflow so you know which way to install it. The size of the filter will be printed on the cardboard edge.
If your filter happens to have a plastic frame, it’s probably a reusable one that you can clean with soap and water. There are various ratings for filters that correspond to their efficiency in filtering certain things from the air.
Check any HVAC filters and replace them.
HVAC filters are similar to furnace filters. Most HVAC filters are located in the return air duct of your system. As with furnace filters, they will have a designated size and airflow direction.
Visit your basement or crawl space.
Look for any signs of water, especially in corners and the edges of basement walls. For crawl spaces, make sure there isn’t a cesspool (breeding mosquitoes) under your house.
Repeat seasonally, then every fall and spring to make sure rain or melting snow isn’t encroaching where it shouldn’t be.
Check your attic space.
You’re looking for water here, too. You’ll want to repeat seasonally until you have an idea of when water is most likely to intrude.
Check your windows.
Again, look for any water penetration around them. Check to see if your window sills feel soft — if so, there may be water leaking in between the sill and the wall. f the windows feel drafty, recaulk them. Caulk does degrade over time. To recaulk, take yourself out for another trip to the home improvement store and purchase a caulk gun and caulk. There are different kinds of caulk for interior and exterior use, as well as caulks for especially humid spaces and caulks for the type of surface you’re caulking (wood, stone, brick). If you can, splurge for the more expensive caulk gun that has a thumb-release trigger. These make it easier to control the caulk flow. Usually, the more expensive guns are the ones that are sold without a tube of caulk already in them. Before recaulking, remove any dried and cracked caulk using a putty knife or paint scraper. Cut off the tip of the caulk tube to allow the caulk to flow out. Caulk all the seams where the window meets the sill. You can smooth out the caulk with a wet fingertip. You should only have to do it again every few years. You can also add weather stripping.
Check your doors.
Check your doors for drafts, too, and add weather-stripping if there isn’t any, or replace what is there if it doesn’t seem to be doing an efficient job. The less drafty your house is as a whole, the better (and more efficient) your heating and cooling system will be at maintaining your desired inside temperature.
Clean your fridge coils.
You know that disgusting, dirty space behind your fridge? Don’t be afraid! Slide your refrigerator out from the wall, unplug it, and give those coils a good clean. If your fridge is connected to a water supply (has an ice maker and water dispenser on the front) make sure not to disconnect that.
Clear your dryer vent.
This is the part of your dryer venting to the outside of your house. (You should clean your lint trap after every use). Clean your vent every six months. Unplug the dryer and (if it uses natural gas) turn off the gas at the wall by turning the valve into the off position (to the right). Pull the dryer away from the wall and locate the vent duct. Disconnect the hose from the dryer. If there is a clamp holding the hose in place, use a screwdriver to loosen the screws. From the outside of the house, remove the dryer vent cover if there is one. Vacuum the duct out from the outside.
15. Check your gutters.
Clean out all the leaves and other debris that gathers there.
