I have a Carrier Infinity Heat Pump, model 25HNA624A003, that had a second compressor put in it approximately 3 months ago. The high and low stage contactors were also replaced. I came home this evening and noticed the following errors when I heard to unit starting and stopping...
11 Events - 72 Thermal Cutout in High Stage
4 Events - 71 Thermal Cutout in Low Stage
3 Events - 85 Low Contactor Open
Browsing the forums, I see that the control board in the unit (version 03) could be the cause of the 71 and 72 codes. As of now, the unit has been running fine for approximately 30 minutes. However, if these errors keep occurring, I plan to have someone out to look at the unit, and if a new board is needed, it would nice to know in advance what the latest version for my model is so that I can make sure I am getting the most recent version. I see a version 15 is out, but is that correct for my model? I came across a service bulletin dated 1/3/06 that said to upgrade the board to version 10, so that does mean anything version 10 or later will work?
Thanks for the help.