My home Rheem system is about 18 years old. The system has been maintained w/ outside and inside coils cleaned regularly and filters changed. I have a friend that is almost done w HVAC classes, as well. Here are the symptoms of my system:

1) Compressor constantly cycles on and off
2) Inside vent air is around 70 degrees
3) Manifold pressure on high side is low and manifold pressure on low side is near normal.
4) Emergency heat, when turned on, cuts the inside blower off
5) doesn't seem that the auxiliary strips function when in normal mode, as well
6) Compressor Amps are OK @ around 7.8-8.0 when running
7) The inside heat strips read 120 v when system is on and when in defrost 230-240 v.

I do realize that heat pump air is not "Hot", as compared to gas or electric heat and outside ambient temp has a lot to do with it, as well. My family is rather low on cash, as I just had surgery on my shoulder, we are trying to get out of this with as inexpensive repairs as possible, for the time being.

We think it may be stopped up orfice either inside, outside or both or possibly a worn out compressor, but as far as the Emergency heat mode, we are at a loss. Any input or suggestions are SO GREATLY appreciated! On any of the issues we may have.