Regardless of how new or old a product is there is always a percentage that will fail.  They can be repaired,  recycled, or simply discarded.

In New Zealand the Fair Trading Act  and  Consumer Guarantees Act protects the rights of consumers.

A percentage of new products will always fail while still under the manufacturers warranty.  In fact, statistically, a product will have a higher chance of failing when it is very new than when it is partway through its useful life.  This is illustrated in the graph of failure rates known as the bathtub curve.

Graph of the bathtub curve

The bathtub curve is a concept that describes statistical chance of when a product fails at different points over its useful lifetime.
Image: Wikimedia Commons

The percentage of products that fail under warranty depends on four main factors: lack of burn in, poor quality, misuse, and poor design, although the latter three will cause failures over the complete product lifetime.

Manufacturers warranty
A manufacturers warranty covers any manufacturing defects but does not cover wear and tear or misuse.  A product should be used for its intended purpose as stated by the manufacturer other it may fail prematurely.  An example of this is the cheaper power tools.  Some of them are sold on the condition that they are for DIY use only rather than for industrial use.  Power tools that can be used in an industrial environment are manufactured to a more robust standard and may have a specific and specified duty cycle.

A warranty is often for one year but some manufacturers are now giving a three year warranty on some of their products.  This is often the case for low value products.

One result of this is that the manufacturers no longer carry spare parts for the low value products if it fails they simply replace it rather than having it repaired.  After three years the product is deemed by the manufacturer to be at the end of its useful life.

Extended warranties
Extended warranties, where an extra amount is paid upon purchase of a product to cover failure beyond the manufacturers warranty, are generally not of any value. Firstly, it covers a period of the product usage when reliability is at its best and therefore a warranty is of less use.  Secondly, the extended warranty conditions are such that very few failures are repaired at no cost.  A percentage of the products would be declined on the basis that the fault is due to wear and tear or misuse.   For the repair organisation administering extended warranties can be quite time consuming.

After market warranties
Warranties are often given on repaired or refurbished products independent of the manufacturers.  The conditions imposed and the length varies but typically they are for one, three, or six months.

Further information