Carrier Central Heat/Air Unit acting strangely
Unit - Carrier FA4ANF030
Thermostat - American Standard 400 Family Digital Non-Programmable Comfort Control
I live in Florida. Last week I went out of town for a few days. During the time I had the unit set to "off." Upon my return yesterday, I noticed that it took longer than usual for the heat to kick in after I turned it on. The house was 62, I wanted 68. It did finally come on and I didn't think any more of it. However, last night I woke up to a weird noise in the house. The evaporator/blower unit was make a very loud electric buzzing noise, but the blower wasn't running. In addition, the outside condenser unit was running as well. There was no heat coming from any of the vents. A few minutes later, the blower did kick on, and heat flowed from the vents. It brought the house up to 70, and then the blower kicked off, but the evaporator/blower unit was still buzzing and the outside condenser was still running. I turned it off before going to work.
When I returned tonight, the house was at 65, I wanted 68. After turning on the heat, the evaporator/blower started buzzing again, but the fan wasn't blowing and the outside condenser didn't come on. A few minutes later, the condenser started going. About 15 minutes after that, the blower finally came on and the thermostat said it was utilizing aux heat.
All of this is contrary to normal behavior. Until yesterday, the evaporator/blower, the fan, and the condenser would all turn on and turn off at the same time. I never saw aux heat used. What is going on and how to I fix it?