I received this in the post today, I’ll certainly be trying to get more details from them about the irregularity.
Just posting it here in case anyone with the PUZ-WM112VAA/YAA doesn’t get the letter.
My installer applied this update when they came to service the heat pump earlier this year. Another owner I know got the same notification from Mitsubishi via email.
Did you hear anything about what it addresses?
I think it was the compressor potentially leaking refrigerant or something. Certainly worth getting the firmware updated. I’ve not noticed any difference in day-to-day operation.
Engineer from Mitsubishi has just been to update the firmware on both units here.
Outside is now running version dd4e while indoor was updated from 1900 to 2001.
Our installer refuses to install updates. I have found 2001 here and it looks easy enough to install on the indoor FTC6 unit by yourself:
But I havent found anything about updating the outdoor unit.
Wow, I wonder how a FW update could stop a refrigerant leak?! It must be serious if Mitsubishi is sending engineers to every affected heat pump, that must be a massively costly undertaking. I bet they wish they had OTA update capability!
It was my assumption that when applying the update via the mainboard with an SD card that no other work is required, but I could be wrong on that…
Indoor unit can be updated with SD card. Outdoor unit requires a specialized device (from what I remember)