I turned our heat pump to Cool and the system kicked on and then went silent after about 15 minutes. The fan stayed on but started blowing ambient air and the actual temp ended up being 10 degrees above set. Turned off overnight and turned back on and the same thing happened, eventually went off and temp stayed the same.

I am located in Northeast, PA. The unit is a York that was installed in 1994. This last winter was pretty rough. I had an energy audit completed, the master bedroom was the only room with an issue with the blower door test. Duct inspection showed some small leaks, nothing that was a difficult repair. I have to insulate the rim joist and that it is. I am wondering if it is time to replace rather than repair. If I were to replace would oil and heat pump vs heat pump electric backup be my best route as the winter is very cold here and previous ones the heat pump plus backup would have trouble unless it was only on backup which became pretty pricey.

I would also love to look at zoning as the upstairs tends to lean toward the temperature extremes more than anything else.