Yes, it's very possible. there are a bunch of places freon could leak, and
not be easy to detect. It's very possible there is a leak in the lineset.
However, as the other fellow wrote, you'd think he could have detected the
leak where the tubes go in and out of the wall.

I'd also suggest to call a second service company. Ask them to come over and
find the leak for you.

Your description "add two pounds and it's cold as ice for two weeks" is
classic description of freon leak.

--

Christopher A. Young
Do good work.
It's longer in the short run
but shorter in the long run.
..
..


"user" wrote in message
...
Hi Folks..

I'm having an issue with one of the AC systems in my house.. For some
reasons only the upstairs unit seems to be leaking freeon.. But I've had
a tech come over, and check for leaks, using a device amde by
Infinicon-Tekmate, that emits a beeping sound when freeon is detected..
However, the tech wasn't able to detect any leaks using that.. Then he
tried using the bubble detector solution, but wasn't able to find any
leaks with that either.. He did this in both places, in the attic near
the coil, and outside by opening the unit near the compressor..

He said that the only other place that the freeon could be leaking is in
the pipes from the upstairs unit to outside, which would involve
drilling a hole in the wall, pulling the pipe out, and replacing, and
then repairing the whole in the wall..

However, when the tech replaces the freeon (with upto 2 pounds of
freeon), the AC is ice cold again, and the last time he recharged it, it
lasted for 2 weeks. Hopefully this time it will last longer, and the
summer in the SouthEast will be over..

I've also replaced the filters and vacuumed the vents..

Has anyone seen this before.. where the freeon leaks over a period of
say 2 weeks, but can't be detected, and upon recharging, it works fine..
for another 2 weeks. ?

Thanks in advance for your help..