Quote Originally Posted by thecomp View Post
I'm continuing to speculate, and I question the leaky condensing unit installed on a membrane roof, neoprene isolators, and onto two PT 4*4. The Trane installation book mentions two ways of installing: isolated or concrete pads or footings at each load point (corners I guess), or neoprene or spring isolators.

Is it possible that the roof location is the cause of the coil leak problem because it allows the unit to move too much.

This is the second condensing unit on this roof and both have gone through countless condenser coils. I have checked the level of this machine to be perfect. I wish my house was so straight.
too much movement could be like vibration, but how much is too much? the spec is < 1 mil on the discharge piping in any direction. i would start to think of it like this: how many coils have you put in this one condensor? (i know you have several machines, but focus on one at a time) it is very difficult to say that Trane has had a "bad run". i work for Trane and they do a pretty good job of letting us know about problems (even if they do not let the general public know). even if they had a bad run, it is very unlikely that it lasted long enough for you to have gotten all/most of them. so it comes down to whether you have not fixed the "real" problem yet (vibration from some source like cond fan motors, compressors, building, etc) or the installation of the new condensors is poor. could be even a combination of both.

is it possible, kinda like graham said, that the unit is not square always? maybe building sway tends to take it out of alignment? (i'm reaching for the sky on this one, but who knows! )

i am not trying to put the blame on everybody but Trane. i am just trying to help open up some other possibilities. i have not heard of an epidemic on the coils. like i said, just certain ones seem to be more prone, but i have never investigated the real reason. only happens when they need it running and i can not shut it down to find out why.