The best way to purchase Harbor Breeze fan parts is directly through the manufacturer. Harbor Breeze has a dedicated customer care department telephone line for this specific purpose.
Depending on where you purchased the fan, you may be able to return it to the store where it was bought for a replacement fan or servicing with replacement parts. Many retailers sell Harbor Breeze replacement parts, such as Lowe's, Sears and Ceiling Fans N' More, and all are willing to accommodate customers with defective merchandise. If the fan was not recently purchased, online retailers such as eBay, Houzz and Amazon.com can be sources of Harbor Breeze fan replacement parts.