My central air unit will work one day, then not another. Or it will
work for a while then stop. By this i mean air is blowing out of the
the vents, but not cold air. Sometimes it does work however. I have
a clean filter and i have tried it on auto and on fan with the same
result. I don't understand how it can work one day and not work
another. ANYONE know why???
Thank You for your time
Just a simple test.
I'm assuming this is a 'central air conditioner' and not a window unit.
By not working I also assume it's not cooling.
Beside the issue of adequate cooling gas, a common reason for intermittent
cooling is a dirty 'A' coil in the plenum.
If you have an access panel, that you can open and find the A coil 'iced'
up, that means inadequate air is passing through usually due to dirt, dog
hair, dust clogging the fins.
A qualified service man will use compressed air and vacuum to clean it.
THANK YOU SO MUCH I WILL CHECK THAT OUT NOW. IT IS A CENTRAL AIR UNIT
AND YOU ARE CORRECT THAT WHAT I MEAN IS THAT EVEN THOUGH AIR WILL COME
OUT IT WILL NOT BE COOL AIR. MY QUESTION IS WHERE DO I FIND THIS
ACCESS PANEL. IS IT IN THE OUTSIDE UNIT OR THE INSIDE ONE IN THE
GARAGE?? THANK YOU SOO SOO MUCH FOR YOUR HELP.
I had a brother in law exactly like that. We never did figure out what was
wrong with him.
Call an AC company. You may be able to fix what's there and not have to
replace the entire thing if you keep running it and fry it.
It's obvious something's wrong with it. Don't run it into the ground. Stop
now and have it diagnosed and fixed.
On Thu, 05 Jul 2007 23:39:04 -0000, firstname.lastname@example.org wrote:
Do you have a separate circuit breaker for your central AC? Is that
breaker on? One winter I turned the breaker off for my AC and forgot
to turn it back on the following May and couldn't figure out for about
24 hours why I had moving air that wasn't cold in the house. Then I
checked the breaker box, and lo and behold, the AC breaker was off. I
flipped it on, and presto, cold air a few minutes later.
On Jul 5, 7:39 pm, email@example.com wrote:
Here's the latest on my problem. It stopped working and checked the
indoor and outdoor control panels and nothing was frozen. It doesn't
look dirty so would the dirt be internal? Do you think it needs more
freon? The outside fan does run and air comes in but just not cold
air all the time.
On Jul 6, 2:14 pm, firstname.lastname@example.org wrote:
Please don't take this the wrong way, but you're so clueless about how
your A/C works that you really should call a professional in. Trying
to do it yourself, you're just going to break it worse than it already
If it needs freon, it has a leak, and any freon you add (provided you
manage to add the freon without blowing yourself to kingdom come) will
just leak out. A professional has a special dye and tools to detect
and fix the leak.
The whole discussion is moot, though. All you keep saying is "IT DON'T
WORK." There is no way to diagnose the problem without more
information, and even then, there still may be no way to completely
figure out what is going on without physically being there.
A little lesson on A/C: Air doesn't "come in." You are not getting
cold outside air when you turn on the A/C. The outside unit compresses
the freon and cools it. The compressed freon flows to a radiator
inside your ductwork in the house, where it is allowed to expand. When
it expands, it gets really cold. Your furnace blower sucks air out of
your house, blows it through this radiator where it gets cold, then
blows it back into your house. The cold air you feel is inside air
that has been cooled.
This radiator in the ductwork (called the condensor IIRC) is the part
that may be full of crud and/or frozen. Usually it is located near the
furnace because that is where the fan is.
On Fri, 06 Jul 2007 11:30:23 -0700, email@example.com wrote:
It was never the control panels that get frozen, it was the A coil
(the evaporator) which is inside the plenum (as they call it, the big
duct coming out of your furnace, which may or may not have a cover you
can take off to look inside. I had to cut a hole in my duct so that I
could look inside. (There are two sides to the furnace, intake and
output, and the A-coil is on the output side, all the time afaik, but
before you make holes, you should be sure that you are at the right
place. If you see two curving pipes going into the duct there, and
the other end of the same pipes go out of the house to the outside
unit, you're at the right end. But I don't think you want to cut the
hole yourself, do you? But if there's a removeable panel, I think
that you could do, although I'm not sure what you woudl gain.
(OT for you, but I probably should have made my hole bigger, but I was
just trying to find out what happened to the water that condensed, so
since I"m a "good boy", I made the hole small. If I ever have to
clean it, I guess I'll have a hole around a hole. I don't even
remember how I patched the first hole.)
You're right in about all of this, but you shoudl have stopped....
You probably wouldn't make these little errors if you had reviewed
this an hour after writing it.
You mean, and heat radiates from it. It's no cooler in temperature
than when it came into the outside unit (and I'm pretty sure it's a
It's a lot like a radiator for sure, in that it has fins and transmits
heat, except that radiators *radiate* heat, whereas this thing absorbs
heat, so I"ll bet no designer or pro would call it a radiator. Still,
it might be a good term to use with the OP because a radiator is
something she's probably experienced with, from cars.
Not out of the house but into the big duct, which is still inside the
house. You know what you mean, but she may run around looking for
something out of the house. Well it might be true if your furnace was
out of your house, if you count the attic or the garage as out of your
house, but even then I think most ducts where cooling is done are in
Doesn't blow it back into the house either, but you call it inside air
in the next sentence, which helps.
Called the evaporator. The condensor is in the box outside, with the
compressor. If you compress a gas enough, it will turn into a liquid,
which is what condense means. The gas becomes hot as you compress it,
but cools off almost to the outside temperature, because it is
The easiest way I remember this is that when you take the valve out of
tire, or when you release your fingers from a balloon, the air coming
out is cool. That's because it's no longer compressed. So the
converse is also true and when you compress air or any gas like freon,
it becomes hot. (Actually when you fill a tire or some smaller
things, you can feel that they become hot, plus the hose from the
pump, even a basketball pump.)
Both inside and outside fins can be dirty. Only the inside will be
frozen because of lack of freon.
And the ducts, if one has a furnace that uses ducts.
You should've took your own advice.
"You're right in about all of this, but you shoudl have stopped...."
The compressor compresses the low pressure gas to a high pressure gas. This
allows it to reject the heat in which it absorbed. As the heat is rejected
the gas is cooled which causes it to condense to a liquid.
I'm not sure what I said that differs from this. I just didn't go
into as much detail. And when I rereed, in this part I'm not
specifically speaking about an AC condenser anyhow, just about gases
and liquids. Applying it to air conditioning was left as an exercise
to the reader. :)
You're right about one thing, she needs to call for service.
However, your description of "How an Air Conditioning System Works" needs
Example, the compressor compresses the low pressure gas to a high pressure
gas where it can reject the heat (that it gained from the inside) to the
outside as it condenses the high pressure gas to a liquid. The indoor blower
moves air across the evaporator where it can absorb the heat from the air,
which is then carried to the outdoor unit to be rejected. This process takes
place when the high pressure liquid hits the indoor metering device and
flashed to vapor. The change of state causes the indoor coil to get cold
where it can absorb heat from the passing indoor air.
Condenser is outside
Evaporator is inside
(for air conditioning)
Could be a lot of things. Dirt in the coils will affect the operation. Low
Freon will too. It is not easily diagnosed no knowing more information. My
advice is to call a service technician. Even a simple job like cleaning the
fins can damage the unit if done carelessly as they bend very easily.
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