You do not have to be a HVAC professional to understand how heat pumps function. If you have one then you should know how it works.
Heat pumps work like regular systems during the AC season. Keep that in mind when you have one installed in your home.
With a heat pump you should not turn your AC system off. Only using the cooling system on a part-time basis can cost you money in energy bills and repair costs to the system. If you turn it off when you are out of the house, your home will soak up the heat that is there and this will make cooling in the late afternoon/evening much harder to accomplish. You will save $ when you let the thermostat decide when cooling is required for your home.
The heat pumps in your home will provide warm air during the time of the year when you need heat. The pump will run for long durations of time. They are designed to operate in this manner.
When it is the coldest outside, frost will build up in the outdoor coil of the heat pump. This will begin a cycle of defrosting. When the cycle is taking place, the outdoor fan will stop running and the compressor will make a humming sound.
You will notice that cool air is coming from the registers. You may also hear a whooshing sound and will see water runoff or steam coming from the unit. These functions are all normal and are related to the cycle of defrosting.
During this defrosting cycle, allow it to do its thing. Do not make any changes to the thermostat. The cycle will take anywhere from a couple of minutes to 10. The time depends on the amount of ice build up on the coil. Once the cycle is finished, the unit will return to the heating function.
If you believe that the heat pump is not working properly, you should call in a professional to evaluate the system. Do not attempt to repair it on your own- you could do more harm than good.
Do not constantly adjust your thermostat. It is best to find a comfortable temperature and then leave it at that setting. There will be more wear and tear on the system if you fiddle with the temp all time. As well, it can be anything but budget savvy to do this.