My electric central heat/cool unit blows constantly but will not blow heat to keep up with the thermostat temp.. what can I check or fix to correct this? Its 28 degrees outside and 39 degrees in my house.. help.

Check your breakers first... second call a heating repairman... because you really don't want your pipes to freeze... they will split... toilets will break when the water in the bowls and tank freezes. The repair costs for that will dwarf what the serive call will cost.

Many electric furnaces have manual reset high limit switches but unless you know what you are looking for, they can be difficult to find. You could also have a bad relay, burnt fuseable link(s), or any of a wide array of problems. With the temperature in the house at 39*, I too would suggest calling in a local professional.