Remove the door, then replace all weather seals
With heating costs going through the roof, here’s an easy way to keep heat from slipping out your doors, too. Take 30 minutes and replace the weather stripping and door sweeps around your steel entry doors. Plan to do this project on a warm day since you’ll have to remove the doors. Steel doors use a compression-style strip for the hinge side and a magnetic one for the knob side and the top. But look at the door and confirm the style of weather stripping on all three sides and the type of door sweep before you head to the store. You’ll find replacement weather stripping in a variety of lengths and colors at home centers and hardware stores.
To remove the door, close it and use a hammer and a pin punch or a thin nail to tap out the door hinge pins. Turn the knob, open the door slightly and lift it off the hinges. When you rip out the old weather stripping, you might find that it’s tacked into place with small brads from the manufacturer. Leave them in place after removing the old weather stripping or you’ll damage the doorjamb. Then shear off the shanks inside the groove with an old chisel (Photo 2) or drive them deeper into the groove with a screwdriver. Press the new magnetic weather stripping firmly into the groove on the knob side and top of the door frame and do the same with the compression strip along the hinge side. To ensure that the strips won’t pull out, pin them with a few 1-in. brads, especially in the magnetic strips (Photo 3).
The sweep on the door bottom is even easier to replace. Pry or slide out the old sweep. Run a bead of caulk along the bottom edge of the door, tap the sweep into place and then staple it at the ends (Photo 4). While you’re at it, you might as well do a quick fine-tune of the adjustable threshold. Adjust all four screws until the door opens and closes without too much drag and any drafts have been eliminated (look for light between the sweep and the threshold with the door closed). Turn the screws clockwise to lower the threshold and counterclockwise to raise it (Photo 5).