We'd like to help improve your experience with the operation sounds from your Opal. Please note, we do not recommend altering the internal components in any way, as that is not how the Opal was designed and tested for use. We recommend only using distilled water in your Opal to help reduce the potential for mineral buildup. It is recommended that you follow the instructions in the owner’s manual for your unit regarding the schedule of running descaling and sanitizing cycles. Using vinegar in the descaling cycle can help break up the minerals as well. It’s important to note that distilled water is different from bottled water, reverse osmosis water, filtered water, or spring water. All of these other options contain varying levels of minerals that can build up in the unit and impede optimal operation. It is recommended that there be at least 4” of clearance in the back, on both sides, and above the Opal to allow proper air flow so that the fan can move air about the unit. These tips will improve performance and resolve any abnormal sounds you may experience.