The issue I’m about to describe isn’t from and an inspection. It is from my own house. Outdoor temp here got down to 31 last night. My Heat Pump on the first floor has been running for a long time and only raised the inside temp by 1 degree. It is a Trane XE1000 model. I checked the temps at the registers and got an average of 95 degrees and found 81 degrees at the return. The inside temp has only gone from 67 to 68 in 3 hours. In comparison, the second floor has an identical system and I get 114 degrees at the registors up there. I’ve never has a problem with this unit until now. We did notice an odd smell when we first turned it on to use it about a week or two ago, but it wasn’t the infamous “Dirty-Sock Syndrom” smell. It was more like a burnt bacon smell, however that went a way. I’m going under the house this morning to look around, because a few days ago, I had found a stray cat coming out of my crawl space that must of snuck in when I had the door open last weekend and forgot to close. I looked around for kittens and didn’t find any, then closed everything up. The crawlspace entrance is inside the garage.