To choose a used washer and dryer, focus on the features you want, your budget range and if a warranty is important. Ask appliance and hardware stores if they have scratched or dented washers and dryers for a discount. Also ask friends, post online ads and search ads.
Many appliance repair shops also sell refurbished, or used, washers and dryers. Buy a brand that Consumer Reports or another trustworthy source recommends. Try to see as many used washer and dryers close together as possible. Make notes on their conditions and prices. The best practice is to test them while they are plugged in and operating. Run the washers and dryers yourself to get a better feel of how user-friendly they are and how easy they are to operate. Keep an ear out for sounds that indicate something is wrong or that the washer and dryer are too old to last long.
If buying from private sellers, look at the general upkeep of their homes. A home in shabby condition indicates shabby treatment of appliances.
Ask about warranties. Buying a warranty is a good idea because a used washer and dryer can be fixed or replaced within that specific time frame, no matter what. Many retailers and appliance repair shops offer extended warranties.