Now that you have a closer installed and/or properly working, and the door’s weather stripping is functioning correctly, the door and frame hardware should be inspected to ensure energy is not being lost through gaps. Do a little hardware maintenance to prevent your money from slipping through the cracks.
1.) Inspect the hinges for wear. If there are any gaps between the knuckles of the hinge, the hinge should be replaced. If the hinges require lubrication, remove the hinge pin and apply a light coating of lithium grease.
2.) Ensure that the lock is securely installed on the door; tighten any loose screws or fasteners. If there is any binding, you may need to adjust the lock in the door. The latch bolt should be lubricated once a year with a graphite or Teflon spray.
3.) Check the latch bolt for wear and ease of use. Be to be sure that the latch engages and secures the door with each use. Verify the latch does not get hung up on the strike which would prevent the door from fully closing.
How much energy is lost through the gaps caused by your hardware?