guarantee
(an oral or written promise that the product will function as intended, or it can be returned for a refund)
- This washing machine is still under guarantee.
- We give you a 20-year guarantee against rust.
warranty
(a written promise from a company to repair or replace a product that develops a fault at no cost within a fixed period of time)
- The company will replace the part free of charge If the car is still under warranty.
- The warranty coverage is 36 months.