I have a goodman heat pump system that was instaled in 1998 before we owned the house. I had a Tech look at it today because it was not making any heat and the air output on two of the vents was very low. He checked the system and found no refrigerant. After leak testing he found several small leaks at the botom of the coil. He told me that this probably could not be replaced and that I would have to replace the entire unit. I would like to know if this part in fact could be replaced and I would also like to know if there are any products on the market to seal the leaks without replacing the coil. As far as the air output at the registers he said that the output was fine and that the rooms stayed cold because we kept the doors closed. I disagree with this. We keep the doors closed because they are so cold. He checked the output by putting his hand over the vent. Is this an acceptable way to check the air output of a vent? I don't feel any air movement at all. I hear the fan running but no air is moving out of these vents.