A heating unit is not working at all, a homeowner will need to get some professional help immediately. There are so many things that can cause this type of problem, which is why having a professional diagnosing the issue is important. The first thing that a professional will do when trying to diagnose this issue is to check the breaker that provides power to the unit. In some instances, an overload on this circuit will cause a breaker to trip. If the breaker is damaged, then an electrician will need to be called in to replace it.