I have a model AC-1511 (15033) 15KBTU ducted heat pump with remote thermostat. When there is no heat (or cooling I presume) demand, the circulating fan runs for about 5 seconds every minute. Other than that it seems to be working okay. I contacted Atwood (Dometic) they told me is not operating properly and I should take it to a service center to be checked. Unfortunately even though it is less than a year old there is no warranty so does anybody have any suggestions on how I can determine where the fault might be?