Hello, I have a couple questions about my heat pump and air handler. Heat Pump: American Standard 4A6H5030G1000AA Air Handler: American Standard TAM7A0C36H31SDB My first question is, do I have a single stage or 2 stage heat pump? I thought it was single stage but now I'm second guessing... I seem to see different answers across the internet. Do I have a single stage or 2 stage air handler? Is there a way I can tell? My Sensi thermostat requires me to identify these and I'm not 100% sure. I've been reading that if I set the temperature 3 degrees or higher above the room's current temperature, the aux heat will come on. Is there a way to adjust this? Wouldn't it still be more efficient to run the heat pump even if it takes longer to heat the house? That being said, when it was 35 degrees earlier, we got home and turned the heat on to 65. The current temperature was 57, so the aux heat came on...I think. The mode selected was "Heat" but "Heating Auxiliary" was also displayed on the screen. I'm guessing the aux heat came on because it's an 8 degree difference. However, the air coming out felt cool. I've felt my aux heat and it's like standing beside a fire. Why did it feel cool? Eventually the aux heat shut off and heat pump started up. Was my heat pump defrosting? That doesn't make sense at 35 degrees does it? How do I know what temperature the heat pump will no longer operate at? Is there a way to adjust this, and is it safe? I've heard of people's heat pumps running until 30ish degrees and I just want my unit to be efficient as possible i.e. have aux heat run as little as possible. Lastly, there is an o/b setting on the thermostat, where I select either o or b. Which do I select and why? Does it even matter since I no longer have a wire connected to o/b? Thanks again!!

Hi - I have a Goodman Heat pump that came with the house. I have two zones supporting the house. I have had a couple of A/C issues and had to replace to coils but today I started to get a loud screeching sound from the heat pump support my upper level. The heat pump is about 9 years old with model GSH130301A. I removed the housing to see if the fan was moving freely - all seems right with the fan. I noticed that the screeching noise starts about 10 minutes after the fan kicked on. The noise seems to be coming from the lower back of the unit. It is loud enough that I can hear it from inside. Any thoughts on what I am dealing with here? Here is a short video of the unit and the noise. [url]https://youtu.be/Xipy_B9ljNA[/url] Thanks