I have two relatively new Carrier units. The larger makes an obnoxiously and abrupt, load "Clunk" when it shuts down. T has been doing this for a while and continues to cool properly. When it is running it sounds fine however. I also just replaced the condensate removal pump and hose in my basement, which seemed to fix my water issue, but did not improve the load Clunk at shutoff. What is this problem and what is the long term potential damage if I do not fix immediately?