Find the schematic for your AC. It probably is with the owners manual or
pasted to the cabnet somewhere. Use that to locate all control components
(particularly thermostats) and verify they are switching at the right
temperatures. Since its 15 years old, I assume it worked for most of that
time and you are not looking at a bad design or insufficient power.

BTW Condensers don't run, they are just passive coils of pipe. Either the
compressor or the fan(s) or both should run. A condenser might make a
little noise from thermal expansion but that does not indicate running only
a change in temp.

If you had a coolant leak, the cold coil wouldn't get cold at all or it
wouldn't get cold enough. How much is enough I can't answer from here.


wrote in message
ups.com...
I'm trying to get an idea of what is causing a problem with my AC unit.
I'm in an apartment condo that has a central unit that heats and
cools. The problem is that when the AC kicks in, the unit cools (the
coils get condensation on them and get cool). After a while, the unit
no longer cools anymore but you can still hear the condenser running.
If you turn the unit off, wait a while and then turn it back on the
same thing happens...it cools for a little while and then doesn't. It
never satisfies the thermostat so it doesn't stop unless I turn the
temp up and then you can hear the condenser stop.

The unit is about 10 - 15 years old, has been cleaned and has a new
filter. Any idea whether I'm looking at a coolant leak, a condenser
problem or something else here?

Thanks,
Mark