Carrier Corporation has several brands that use the same part numbering system. The brands are Carrier, Bryant, Payne, Day & Night, Resco, BDP. The parts used in this line of equipment are identified by the product number located on the unit nameplate. Sometimes there will also be a series number on the nameplate. All of these numbers and letters are used for parts identification. If you look at the picture of the nameplate below you will see a serial number, product number and a model number. If you look at the model number and product number you will notice they are very similar. The model number is PA13NR024-H. Carrier made several versions of this model and designated any change in parts used during the manufacture of the equipment with the product number. The product number is PA13NR024000AHAA. The additional letters in the product number designate changes during the manufacturing process. With this number we can see the exact part required for your application. You can contact Shortys HVAC Supplies at parts@shortyshvac.com with the information from your equipment nameplate and we will be happy to identify the factory replacement part for your repair.