My heater only works on # 5 position . Last year # 1 position quit working but #2 thru # 5 worked fine . Last week they all quite except # 5 position which is high . I thought it was the switch so I pulled it apart and it looks fine . I dont see anything that can really go wrong with it . So I am wondering if maybe the heater fan is the problem ? Has anyone out there ever had this problem ?