Warranty usually means that if regular care and use of an item is followed that in an event the equipment fails to function to the specifications or random malfunction, the manufacturer will shoulder the repair of the item (sometimes it covers only the service but not the parts)
A guarantee USUALLY means that if you are not satisfied by the performance of the item, you may return it for your money back or another item.
• noun: (pl. warranties) 1 a written guarantee promising to repair or replace an article if necessary within a specified period.
• noun: 1 a formal assurance that certain conditions will be fulfilled, especially that a product will be of a specified quality.
Actually the error here is that most native speakers use them interchangeably and it has nothing to do with British, American or any other type of English.
'Warranty' has a time limit, e.g. for 12 months... and may be extendable to 24, 36 or 48 months for example.
'Guarantee' is to a standard of quality and is not time bound... and is non-extendable.
Warranty means they will Repair it, and no Replacement.
Guarantee means if it is not Reparable they will Replace it for New one.
A warranty is a promise or guarantee given. A warranty is usually a written guarantee for a product and declares the maker's responsibility to repair or replace a defective product or its parts. A guarantee is an agreement assuming responsibility to perform, execute, or complete something and offering security for that agreement. It is a promise or an assurance, especially one given in writing, that attests to the quality or durability of a product or service, or a pledge that something will be performed in a specified manner. A guaranty is an undertaking or promise that is the answer to or payment for a debt or default. A guaranty is also something given or held as security until a debt is paid or the performance of a duty is fulfilled. By the way,...