It seems like my heat pump blows nothing but cool air out of the vents. It is below 10 degrees out right now. I have an them. Het setting on the thermostat but when I switch to that setting the air from the vents feels cool or just not very warm. It also seems as if my furnace never shuts off. Does it sound as if there is a problem. We try to keep the setting at 68 but it is only keeping the house around 64 to 65 degrees.