Different manufacturers have different locations for the model numbers on their heat pumps. For example, Bryant heat pumps have the model number listed on a rating plate sticker just above the back-seated service valve connections. Bryant heat pumps also have the model number in the owner's manual.
For Rheem heat pumps and air conditioners, the model number is located on the inside front top cover on the indoor part for split systems, while the model number for outdoor units is located on the back of the system. It is important for consumers to know where the model number is located on a heat pump so that they can troubleshoot the system more easily should a problem arise.