I have a Trane heat pump heating and cooling system. In winter when the tempreture is below 32F, the out side unit is making loud noise, very loud humming sound. That loud that bothers my neighbors. When I pure hot water on the out side unit and water gets into the fan and other parts the loud noise go away. What can cause this? Do I need to change the outside unit? It is most likely going to cost me more than $2000 :mad: and I need to avoid that. Any Idea?