Vaseline is one do-it-yourself solution for gaps that develop in a refrigerator door seal. It helps restore the rubber grip of the seal so that cold air does not escape.
Condensation in the refrigerator or ice crystals on foods in the freezer are signs that gaps may have formed in the seal on the door. Owners can test the door seal by placing a dollar bill where the gasket should seal against the compartment and shutting the door. If the bill falls out, a gap has formed in the seal. Applying a thin coat of Vaseline to the seal where it touches the freezer or refrigerator compartment should solve the problem.