Heat Pump Problem
I live in CT and have a heat pump system that is approx 15 years old. When the system runs in the AC mode it blows warm air. I ran the system in the heat mode for about 10 minutes and it blew warm air (I think the temp was what it normally is in the heat mode) I shut it down and let it sit for about 10 minutes. I then ran it in the AC mode again and it still blew warm air. Before I call a repairman, is there anything I can do/check to see if the reversing valve is working properly? OR Determine if the thermostat is operating properly? OR does the system need to recharged? And if so how do I find the leak? OR what else should/ can I do?