# Central air conditioner - not blowing cold air



## Lynnette (Feb 9, 2006)

What could be causing this? We cleaned the filter, and not much change, now we are leaning towards it being low or out of freon (sp?) Is there anything else that could be causing this?


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## tinknal (May 21, 2004)

Is the compressor coming on? I just fired mine up for the first time this year. The breaker tripped about 15 times before it finally started up.


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## Lynnette (Feb 9, 2006)

tinknal said:


> Is the compressor coming on? I just fired mine up for the first time this year. The breaker tripped about 15 times before it finally started up.



As far as I know everything mecahnical is in working order. We have had it on for about a month and it just all of the sudden stopped working properly. It blows cool air, not cold, and nowhere near the temperature that it should be as it does nothing to cool the house.


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## moopups (May 12, 2002)

Make sure the heat transfer fins are not clogged or have any air restrictions. I saw one case where a kid constantly tossed a basket ball against them because he liked to see how big of a space he could accomplish with each throw.


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## Lynnette (Feb 9, 2006)

moopups said:


> Make sure the heat transfer fins are not clogged or have any air restrictions. I saw one case where a kid constantly tossed a basket ball against them because he liked to see how big of a space he could accomplish with each throw.



Thanks MooPups, Thanks everyone

Please keep the ideas coming folks, I will print this off before I leave work and show it to DH, as he is the resident handy man.


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## agmantoo (May 23, 2003)

Can you see the evaporator coil (the one in the house if it is a split system)? Is it iced over on one side? If so, the unit is low on freon.


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## Lynnette (Feb 9, 2006)

agmantoo said:


> Can you see the evaporator coil (the one in the house if it is a split system)? Is it iced over on one side? If so, the unit is low on freon.



No kidding? I will have him look at that next, I am totally clueless when it comes to these things adn DH is inexperienced with AC but with a little research and/or guiding hand can fix anything. Thanks!


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## Hammer4 (Oct 13, 2005)

Start with the basics....

Is the outside compressor running? Check that the fins aren't bent, clogged with weeds, grass clippings, dirt daubers, whatever.

Then go in side...pull the furnace filter, check it, clean it if its reusable or replace it if its not. 

Feel the freon lines coming into the evaporator...one should be nice and cold, the other should be room temperature or so. 

If one isn't nice and cold, you have a compressor problem with the outside unit, or low freon. 

Make sure the drain line is unclogged and that the condensation can get out of the drip pan under the evaporator....I have had the line plug up or the drip pan opening leading to the drain line plug up, there was so much water in the drip pan it was leaking down the inside of the furnace....an a/c unit first has to DRY the air before it can beging to COOL it...what is your humidity in the house? You don't have any windows or attic fans left on by chance do you, any loss of that cool dry air will make it much harder for your system to work. ( I have seen the attic fan thing many times, a friend thought it needed to be on for the a/c to work good, I explained to him he was just blowing his cooled air outside....my wife did it as recently as yesterday, I got home and BOTH a/c units were on, as well as the attic fan..I said, lets review this again...either turn the a/c on, close the windows, and shut off that fan, or vice versa...but don't do both at once...)

A lot of times you can remove a few sheet metal screws and remove the metal around the evaporator ( a frame shaped heat exchanger normally mounted above the furnace heat exchanger in most installs ) and inspect it for cleanliness.....it needs to be nearly spotless, no hair/dust/mold/etc...this is what cool the air that cools the house.


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## moopups (May 12, 2002)

There is an entry in the links library concerning appliance repair, AC units are also covered. www.repairclinic.com/0003.asp


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## Lynnette (Feb 9, 2006)

Thanks - I knew I could count on you guys to steer us through this one. I will let you know how it goes.


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## WayneR (Mar 26, 2007)

Lynnette,
While your at it,look for oily spots on any of the equipment, especially where the lines connect to the condensing unit and the evaparator (inside).

If you find a spot, mix up some liquid dish soap and a little water. Brush it on the suspect area and watch for bubbles (leak) . If the unit is low on refrigerant, make sure that the leak is found and repaired. Feeding it every year wastes money and refrigerant.

Be sure the evaporator is clean as Hammer suggested. If clogged ,this could also cause the icing condition mentioned earlier.

Is the condenser (outside) fan motor running fast enough? WITH THE POWER OFF check for free movement of the blades. You should be familliar with the inside airflow (blower).


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## hunter63 (Jan 4, 2005)

Hammer4 said:


> Start with the basics....
> 
> Is the outside compressor running? Check that the fins aren't bent, clogged with weeds, grass clippings, dirt daubers, whatever.
> 
> ...


All good advice. 
What brand is it?
Sounds like the compressor isn't running , so check the copper lines going in to the out side unit, big one should be cool/cold maybe condensation one it.
Small line should be warm to the touch.

Some units ( Lennox for example) have a "high limit switch".
Will be on the small line inside of the outside unit. Has reset button on it, to reset.

While your in the outside unit (I am assuming that if your gonna fool with it your self, or DH, that you have some working knowledge of 220v a/c electric stuff), If not, call the repair guy, we gotta eat too.

Check voltage at the contactor. ( The 2 big wires coming in from the house/disconnect will go directly to a black contactor,) this is the line side. ( L1-L2
Should have 220v from house across these terminals and 115v to ground, from each side.

Next see if the contacts are pulled in, This means that you also have 200v on the other side of the contactor (T1-T2)(if outdoor fans runs, it probably is).
If you do, clamp the amp probe around the one of the big wires going down to the compressor. Should be 8 to 15 amps ( on most residential units).
If not, the compressor isn't running.
It may have a bad capacitor, silver or gray can looking thing, round or sorta flat with rounded sides, with severals running to it, might be one or two.

If one it will say "Fan-C- Herm", see if there is fluid running out of it or it is bulged out, if so "bad", will prevent compressor from starting. 
If two, have to determine which one is for compressor ( most likely the big one).
If these "look" OK might still need to have checked w/ a meter.

If all these thing check out OK, might be the compressor is DEAD, this is a bad thing.


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## Lynnette (Feb 9, 2006)

I printed this thread yesterday for DH, and tis morning decided to have him look through the thread himself to get the new posts, hopefully we can get this figured out. Thanks everyone, it is pretty miserable in our house, and it is only getting hotter. Outside temp yesterday was 97 degrees in the shade! Inside temp has been averaging 87 degrees with the fans on and windows covered.


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## Hammer4 (Oct 13, 2005)

Lynette provide us with some feedback....

Is the outside compressor unit coming on? 

If not, it might be low on freon so the safety switch is keeping it from coming on (modern auto systems have this as well, btw), or the fuse/circuit breaker/disconnect might be blown/tripped/shut off.


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## Lynnette (Feb 9, 2006)

DH says everything mechanical is running, no leaks, he "meticulously" cleaned everything out, and the system is blowing more air, although the temperature of said air has still not changed. He checked out this post and read everything over. He is going to go over it again, he worked on it for 2 hours, and then had to get some sleep, (3rd shifter), he will be back at it again, perhaps he missed something, he did mention something about the compressor possibly being out of oil. It may be time to call the repairman, although we can't afford to even contemplate that so we may just be in for a hot Summer and have to survive with a single window unit air conditioner. Thanks for all your help, he has not thrown in the towel yet. I will try to keep you updated.


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## farminghandyman (Mar 4, 2005)

if it is out of oil it is out of freon, the system is more than likely a sealed system, and if it happen all at once it developed a leak and dumped the freon or it iced up, either way shut it off, you can try again, but to run it like it is may do more damage to it. the coil in side the furnace or air handler is where it ices up, hard to see that coil with out taking things apart, in the furnace or air handler,(air handler is a box that basically has a fan in it no heaters) kinda looks like a furnace, tho.

let it set 24 hrs and see if it works then if it does then it was probably iced up, that could be caused any a number of things including it leaking on freon, but air flow and clogged filters are the first suspect place, if you have a multiple speed fan, is it set on low speed, turn it up higher speed, and if you can run your fan continuously, if it is icing a little it will melt it off when the ac cycles,

if it is not iced up do to air flow or extreme humidity, you will need to call in a AC repair man, there not a do it your self fix normally, or you need some back ground in AC, or refrigeration, the freon is not sold unless your licenced.


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## hunter63 (Jan 4, 2005)

Lynnette said:


> What could be causing this? We cleaned the filter, and not much change, now we are leaning towards it being low or out of freon (sp?) Is there anything else that could be causing this?


Do we have a solution yet?


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## WayneR (Mar 26, 2007)

Don't know why they don't put access panels on the sides of these things.
It would be a lot easier to clean and check for leaks as well as checking the capillary tube(s)-metering device.

Then contractors build walls around these things so you can't even get to them! :flame:


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## hunter63 (Jan 4, 2005)

Thats why all service men/women should have a third arm/hand, with full 360 degree movement, growing out of the middle of his/her forehead, so as to able to "get at" that stuff, and see it at the same time.
I could tell you some stories..........................


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