Heat does not kick on all the time
Temp is 17 degrees below thermastat setting, any advice?

Check to see if you have electricity to your unit.
Since I have no idea as to what kind of heat you use it is very hard to give you any good advice. So the only advise I can give you now is to post more information about what is happening when you turn up the thermostat, do you hear buzzing coming from the furnace if it is a furnace.