Octavia's Owners are often faced with an unknown hum of air conditioner, which is especially clearly heard at low engine speeds (less than 2,000). All components of the air conditioning system are functioning properly and the refrigerant level is normal.
The manufacturer reports that the noise of the air conditioner at low engine speeds in the Octavia code is normal sound. The sound sounds are due to the fact that the AC compressor is not fully loaded. Similar sound is observed in other models of the Code, and in each case it is not a malfunction.