I did some more poking around as it seems my heat pump still isn't working right. I took the panel off the outdoor unit and saw that one of the LEDs was lit up; it was indicating the system was in "high pressure lockout". I found an installation manual online which said that if the high pressure switch is triggered 5 times within one thermostat setting cycle, the system will shut down and go into high pressure lockout; this is why I've only been able to get it working again if I disconnect the power at the circuit breaker and turn it back on. It works fine in cooling mode but if I try to run it in heat mode the compressor will only run for 5-10 seconds then shut off. Searching some more online, it might be the thermal expansion valve but I think at this point I probably need to call a technician to come out and service it. Damn.
