A range that’s been running fine on light, everyday use can reveal marginal issues once it’s pushed into extended, back-to-back holiday cooking — a burner that was clicking a little longer than normal before lighting, or an oven that was baking slightly unevenly, tends to become noticeable exactly when you can least afford downtime.
A pre-holiday check — clean burner ports, an oven temperature spot-check against a separate thermometer, and a look at the door seal on an oven you’ll be running for hours — catches most of these before they become an actual failure mid-meal-prep.