Have this humming sound too. VIN 257xxx. It's a non-issue for me. It's been hot here in Chicago, and it either comes out for what I think would be to cool the battery, or if the A/C is running. I haven't tried it with heater mode yet. It's a low buzz and once the cabin gets cooled to the proper temp the humming noise goes down to almost zero.
Yes, I second what @Deutsch100 wrote: You have NOT the same problem we are discussing here. You are among the lucky people that have a "normal" Tesla! Enjoy it!