According to Nance Lovvorn of Lovvorn Consulting Services, Birmingham, Ala., "The observed median service life of heat pumps if only removed due to failure [not replaced for efficiency reasons] was approximately 26 years." Lovvorn's information came from a 2001 Alabama Power Co. report, results from which were included in his paper, "Increasing Consumer Confidence in Heat Pumps."
This 26-year median longevity is a far cry from the early days of heat pump installations, particularly in the 1950s and 60s, when early failures led to many redesigns and poor public perceptions of the product.