I have two hvac units. And both have had problems this week. Unit #1, it cools but makes a squealing sound. Is it bad to run it when it's like that? It's been over 100 degrees... Unit #2, stopped cooling yesterday but will blow air. We checked the circuit breaker and also the box on the wall next to the unit. When we turn the air on, the fan does not move and I can feel heat coming from the bottom of the unit. Fan does move when we touch it. Your help is appreciated! Thank you!