Try to locate where the sound is coming from. If it’s coming from the inside unit, turn off your air conditioner, check the air filters and clean them. In order to clean the filters, consult your user manual as each model may have different instructions. If you’re having trouble finding your manual, download it here using your product’s model number.
If there is a continuous and loud squeaking, squealing, or screeching sound coming from the outdoor unit, turn off your air conditioner. The outdoor unit’s compressor or fan motor may have ceased working properly. If this is the case, contact an authorised service agent.