A stove or oven can last 15-20 years, making repairs a good investment for most of its life. Element, igniter, or sensor replacements are generally cost-effective. However, a major failure in the electronic control board on an older unit (10+ years) can quickly become expensive. Consider replacement if the frame or door seal is warped, the glass is cracked, or if two or more major components (e.g., control board and both elements) fail at the same time.