Little hole on my reverse osmosis faucet makes a gurgling noise

The little hole on your reverse osmosis faucet is called an air gap, and it is designed to prevent backflow of water from the sink or drain into the reverse osmosis system. The gurgling noise that you are hearing from the air gap is likely due to air being sucked into the system as water flows out of the faucet.

This gurgling sound can occur if there is a blockage or restriction in the drain line that is causing air to be pulled into the system. It can also occur if there is a problem with the air gap itself, such as a buildup of debris or mineral deposits that is affecting the flow of water.

To fix this issue, you can try cleaning the air gap to remove any debris or buildup that may be causing the gurgling sound. This can be done by unscrewing the cap from the air gap and using a small brush or toothbrush to clean the inside of the gap. You can also try checking the drain line for any blockages or restrictions and clearing them if necessary.

If cleaning the air gap and checking the drain line does not resolve the issue, you may need to consult with a licensed plumber or reverse osmosis system technician to diagnose and fix the problem.