Comfortmaker heat pump split unit?

ok, so that's what I have---my problem is when it get's just a bit cold--not quite freezing, the aux heat clicks on and off on the thermostat monitior inside where I adjust the temp---and the unit outside clicks like clockwork right along with the aux light flipping on and off on the thermostat. I just bought this house last year and never had a problem last winter and it didn't do this. Any idea on what the problem could be? Also I live in SC, so it doesn't get really cold, but if it's slight cold, like tonight it's around 34 degrees----it's doing this. Please give me some hints. I work weird hours so it's gonna be hard to get someone here when I'm home. Thanks a bunch!