Diagnosis
That’s usually normal operation, especially right after startup or shutdown. It’s the sound of refrigerant moving through the coils as the system pressurizes or depressurizes. A constant, loud gurgle might point to an installation issue.
How to Fix It
First, check that the unit is perfectly level, front-to-back and side-to-side. Use a small bubble level on top of the unit. If it’s tilted, the water from the coils might not be flowing smoothly into the drain pan or bucket, causing it to ‘waterfall’ and create noise. Adjust the feet on the bottom until it’s level. Second, ensure the water bucket is fully and firmly seated. A slightly misaligned bucket can amplify internal sounds.
If That Didn't Work
If the gurgling is accompanied by poor water collection or freezing (see above), it could indicate a low refrigerant charge, where the refrigerant boils too early in the cycle. That’s a repair issue. But if it’s just noise and it’s working fine, it’s likely just the sound of the system doing its job.
Heads Up
These units are generally quieter on ‘Low Fan’ speed. If the noise bothers you, try that setting. The gurgling tends to be more pronounced on ‘High Fan’.