In April, F. W. Lang Company (Lang) purchased an ice cream freezer and refrigeration compressor unit from Fleet for $2,160. Although the parties agreed to a written installment contract providing for an $850 down payment and eighteen installment payments, Lang made only one $200 payment upon receipt of the goods.

One year later, Lang moved to a new location and took the equipment along without notifying Fleet. Then, in May or June of the following year, Lang disconnected the compressor from the freezer and used it to operate an air conditioner. Lang continued to use the compressor for that purpose until the sheriff seized the equipment and returned it to Fleet pursuant to a court order. Fleet then sold the equipment for $500 in what both parties conceded was a fair sale. Lang then brought an action charging that the equipment was defective and unusable for its intended purpose and sought to recover the down payment and expenses incurred in repairing the equipment.

Fleet counterclaimed for the balance due under the installment contract less the proceeds from the sale. Who will prevail? Why?