You are forgetting one basic precept of waranties that can apply regardless of the product manufacturer: If you install it yourself, the waranty is voided! Unless the company specifically advises that users "can or may install after-purchase parts and not void the waranty", any part installed by the buyer can immediately void the waranty in many states. Your state may or may not have established purchaser protection laws that would over-ride the waranty statements. You will have to investigate your rights under the laws applicable in your home area to be sure.