We are happy to provide guidance with Opal sounds. When your Opal is in need of defrosting, it may start to squeak as ice starts to build up around the mechanisms. The defrost cycle is automatic and may take 10 to 45 minutes. The screeching you're experiencing can be the result of the appliance needing to be descaled. To descale, fill the reservoir with hot vinegar (100-120°F) to the max fill line and run up to three cleaning cycles. When using vinegar, leave the vinegar in the unit for 18 hours and set a vinegar-soaked towel on the ice chute overnight to further dissolve any mineral build-up. Clean the sensors with vinegar and wipe clean with water. After draining the vinegar, run three rinse cycles using fresh water for each rinse. If the tips provided do not help, please contact Opal Ice Maker Support by calling 1-866-907-6718.