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[email protected] July 12th 06 08:06 PM

AC unit stops cooling but keeps running
 
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


Stormin Mormon July 12th 06 08:21 PM

AC unit stops cooling but keeps running
 
Impossible to say for sure over the internet. But from what you
describe, it sounds like it needs professional cleaning.

--

Christopher A. Young
You can't shout down a troll.
You have to starve them.
..

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



PipeDown July 12th 06 09:00 PM

AC unit stops cooling but keeps running
 
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




CJT July 12th 06 11:19 PM

AC unit stops cooling but keeps running
 
wrote:

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

My guess is the compressor is overheating and thermal protection is
turning it off. When it cools, the protector resets.

Lubrication might help (although most are permanently lubricated
nowadays), as might clearing anything blocking air flow around the
compressor (e.g. debris and vegetation). I would also check that
the voltage at the compressor is correct -- too low or too high can
cause overheating. And you might also try replacing the run capacitor
if it has one, especially given its age. Beyond that, it's probably a
forklift job (i.e. replacement).

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

Stormin Mormon July 13th 06 03:46 AM

AC unit stops cooling but keeps running
 
Text inserted.


"CJT" wrote in message
...
wrote:

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

My guess is the compressor is overheating and thermal protection is
turning it off. When it cools, the protector resets.
CY: That sounds reasonable.

Lubrication might help (although most are permanently lubricated
nowadays),
CY: The compressors are typically lubricated with oil mixed in with
the freon. However, the fan motor often has oil ports. Also, a dirty
or dusty condnsor can cause compressor overheating.

as might clearing anything blocking air flow around the
compressor (e.g. debris and vegetation).
CY: Excellent. Or anything over the top of the unit, such as deck,
awning, roof, etc.

I would also check that
the voltage at the compressor is correct -- too low or too high can
cause overheating. And you might also try replacing the run capacitor
if it has one, especially given its age. Beyond that, it's probably a
forklift job (i.e. replacement).
CY: I can think of a few things that can be a problem -- and
repairable. So, it's time to call a HVAC service company out. May very
possibly be fixable.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .



Richard J Kinch July 13th 06 09:13 AM

AC unit stops cooling but keeps running
 
I'm in an apartment condo that has a central unit that heats and
cools.


Condo? Water source on the condenser? Valve to that closed?

Mowgus July 14th 06 02:57 AM

AC unit stops cooling but keeps running
 
Thanks for the info everyone. First off, it was cleaned professionally
so that one is out. And yes, I confused condensor with
compresser...brain fart...the compresser continually runs but cooling
drops over time.

As for the condo question, the valves are open (double checked that
one, and it does cool initially ;) ).

With the age of it I'm thinking it might need replacing. Partially
because it's a b***h to work on due to it's design (and the fact it's
jammed in a space barely big enough for it, let alone my sweaty paws)
and the contractors says that it'll be minimum $800 to fix it. $800 on
a 15 year old unit doesn't seem like a wise move.

Thanks again for the advice.



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