If you own any of the models listed here and your systems battery is overheating, check your models serial number on Apples website
replacement battery program. The iMac 21.5 Inch Late 2015 1.6 GHz Core i5 5250U, iMac 21.5 Inch Late 2015 2.8 GHz Core i5 5575R processor, and
iMac Core i5 2.8 GHz 21.5 inch 5K Core i5 5575R processor October 13, 2015.
The A1419 Late 2015 Retina 4K
A1418 EMC 2833 Late 2015 Retina 4K
iMac 21.5 Inch Late 2015 3.1 GHz Core i5 5675R processor 4K
The iMac Core i5 3.1 GHz 21.5 inch 5K Core i5 5675R processor
iMac 21.5 Inch Late 2015 3.3 GHz Core i7 5775R processor 4K
iMac Core i7 3.3 GHz 21.5 inch 5K Core i7 5775R processor
iMac 27 Inch Late 2015 3.2 GHz Core i5 6500 Processor 5K Retina display Model A1419 EMC 2834
The iMac Core i5 3.2 GHz 27 inch 5K Core i5 6500 processor iMac Retina 5K Late 2015