If you were to turn your HVAC on in an attempt to cool off your home only to find that the air that it is blowing out is not actually cold at all, chances are that something or the other has gone wrong. It can be really easy to panic in situations like these since you might be afraid of the level of harm that can come to your home if you are unable to maintain a consistent and comfortable temperature not to mention the negative impact that this would have on your day to day routine to boot.
In spite of the fact that this is the case, instead of panicking about what could potentially occur, you must start using a DIY approach to ascertain the cause of the problem at the end of the day. It is important to note that problems with heat pump are quite similar to cooling related problems in that the chemical that creates the desired temperature might be to blame. With cooling, you would generally use a refrigerant to cool down the coils and the fan would blow air past these coils into your home thereby creating the desired cooling effect.
Hence, the best thing for you to do here would be to think about replacing the refrigerant. All you really need to do is to open up the refrigerant pipe, connect a tank of refrigerant to it and then let the tank fill the refrigerant back into the unit. You should let the air conditioner run at the coldest possible setting when this happens in order to get the refrigerant running and this will result in the best possible outcome all things considered.