HVAC heats, will not cool

Thanks in advance for any advice this forum can offer. Our system has been blowing heat tremendously all winter long, but now that spring and humidity are here we have no A/C. The outside fan is not turning, but the pilot light in the furnace unit in our garage is on and air is blowing out of the vents. No circuit breakers are tripped.
Here are the system details:
- The garage unit is a Rheem RCBA-3765AS17 - The outside A/C unit is a Rheem Classic X High Efficiency - The thermostat is a Hunter 44360 that I installed this past fall after the original unit failed
I have posted some photos of these units at Flickr in case anything shows up that could be useful to an expert:
http://www.flickr.com/photos/davedonohue/sets/72157600024185970 /
I am assuming that the outside unit not spinning is the root of the problem. If there's some DIY aspect to this, I'd be thrilled, as I've paid a lot of home repair bills lately and would love to save some cash. At the same time, if it's something that an amateur shouldn't tackle, then I won't.
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Bubba would be able to handle this better than I Nice pictures though

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Thank You daytona For once I get to say it and mean it. "Replace the thermostat. Its almost always the thermostat (installer)"
Now, lets point out a few things according to your post. 1) The heat worked all winter long 2) Spring came around and No A/C to be found 3) The outside fan is not turning 4) The pilot lite in the furnace is on (not that I really care) 5) Air is blowing out of the vents (I guess thats why the heat worked) 6) No circuit breakers are tripped 7) The thermostat is a Hunter(Eww, I going to take one brownie point away for that) **NOW here comes the key point so PAY ATTENTION!**
8) When did YOU say that YOU replaced your thermostat? 9) Why did your A/C work last year? Bubba
wrote:

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Are you sure you've found and checked ALL of the breakers. Most systems are fitted with one more breaker than can be found on a routine inspection ;-)
The outside unit most likely contains two main parts. The fan which you say is not turning. There's also a compressor. Is that running? You should be able to hear it while standing by the unit.
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How many AC breakers are not tripped, and where are they?
Do you know that you probably have a breaker outside, maybe on the wall next to the condenser unit? So make sure that is closed. Mine has tripped a couple times over the years, though I never found out why and never had to repair the AC.

So the AC has never worked since you connected the thermostat? Time for you to review that.
There may be a high pressure switch inside the unit outside that tripped, or some other protective device.
Do you know how to use a meter?
There are a lot of ways to go about this, becuse there are several parts and in theory any one of them could cause trouble.
You need to measure the voltage at the compressor, on the 400VAC range, or some range greater than 240. Don't touch any copper wires with your fingers. This will verify if all the breakers are closed and working right. Although you could save this for later and work on the 24 volts circuit first. If you are looking for 24 volts at the contractor, use your 400 volt scale and don't touch anything except the plastic handles of the probes. Because you might end up touching 240 volts and you dn't want to blow the meter.
If you don't get something around 220AC at the compressor when the thermostat is calling for cooling, figure out how the circuit for the contactor is wired. The contactor is a high-current relay under the cover panel of the condensor. There should be wiring diagram in the papers you have, although I just found one stuffed into a space in the condensor itself.
The control voltage for the contactor is 24 volts. The contactor has loads of screws where wires can be attached and it can be hard to tell which ones are which. So you might want to measure from other parts.
Maybe the best place** to measure is where the wire from the thermostat comes in, but the last time I did this, that led to wire nuts, and for some reason I didn't want to take the wire nuts off. Of course that was a friend's house, so maybe that's why. Anyhow, in this case there was 24 volts there (AC I'm 99% sure) but the contactor wasn't closing. **This is especially true in your case because you replaced the thermostat, and if you did it wrong, there won't be 24 volts at the thermostat wire outside. ***Getting ahead of my story a bit here, somehow after I took off the wire nuts, on wires that were only attached 8 inches away, somehow I shorted the two thermostat wires outside. My friend said he heard a click (which would have been a spark, but I didn't see or hear anything.) But the thermostat voltage went to zero, and I had to replace the AC fuse at the furnace. In this case, there was a spare taped very near by. But be more careful than I and you won't blow the fuse.
If you stare at the contactor for long enough, you'll figure out what some of the screws are for, at least. The big electric cable with 220v attaches to two of the screws, and your meter should show 220 there. Then right across, symmetrically sort of, are the connectors that should have 220 when the contactor is closed. If there is 220 at the house cable side and zero on the other side, the contactor is not closing, and that means there either is no 24 volts to run the contactor relay, or the 24 are interrupted by one of the many things, mostly safety devices that are in the same area.
You can test the 24 volts when the 220 is off, and that might be a very good idea since 24 won't kill you and 220 can, especially if the grass is wet outside, or if you touch the metal case while you touch either of the 220 wires. There is no GFI on 220 volt circuits, no protection there.
There is a temperture cutoff, a high pressure cutoff, a low pressure cutoff, and maybe a couple more. They were all listed on the picture or diagram in the papers that come with the condensor, or glued inside the cover, or folded and stuck into the crack inside. Oh yeah, he also one of the electric company provided radio controlled disconnects, for when there is high electric usage. I couldn't open that, and my first idea when the 24 volts disappeaed was to think that the power company had turned off the 24 volts at that box. But with the meter one could see that there was no voltage even where the 24 volt wires first came into the box, that it wasn't the radio=disconnect that was disonnecting.
I used the voltmeter to work my way from where the thermostat wires came in (There are only two pairs of wires coming in, the 220, and the thermostat wires.)
I leave one probe, say the black, in the same point, and move the other probe closer and closer to the contactor, to see where the 24 volts fails. I use a wire with alligator clips on both ends to keep the black probe connected. That way I don't have to control two probes and can use all my energy to keep the red probe where it should be, and I don't have to worry about falling over and to keep my balance, grabbing on to something that turns out to have 220 volts.

When I blew the fuse above, I myself didn't touch anything.
Just make sure you're in a comfortbable postion so you don't start to fall over and then grab something, so that you have control over where each hand is, and you don't put it on something you don't intend to keep your balance. I sit on my tush with my legs folded, and for me that is very comfortable and stable. I would be afraid to do this sort of thing on my knees, because I wouldn't think it was stable enough for when the 220 volts was on.
It turned out that the high-pressure, iirc, switch had tripped, and in this model it had a big red rubber cover, that covered a reset button and all I had to do was push the button. But I don't feel I wasted time checking everything else and blowing the fuse etc. Now I know his controls inside and out.
His AC worked fine that day, but this was the very end of the summer, and he hasn't used it since. Whether it will continue to trip, I don't know. I sort of doubt it.
Your pictures show the inside of the furnace. The only thing in there worth checking is whehter 24 volts is going to the AC outside when the thermostat calls for cooling. This location may be marked on a diagram, but it's a lot easier to find outside, inside the condensor case, where there are only two pairs of wires coming in, 24 and 220.
Hmm, there was another photo that might have been this, but when I went to enlarge it, it said "The photo you were looking for has been deleted.
You might like to ask DJ Otter Creek about it!
Here's a link back to your home page. "
This post is not in the most logical order, for the sake of time, so if it is confusing, write back with specific questions.
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wrote:

I wasn't clear enough. It's been 20 years since I replaced my thermostat, and I don't remember if there is a separate wire for the AC, let alone if your wire has a separate wire for the AC, but if there is one, it's time to review if you connected it right.

I mean, because you don't want to kill yourself.

This is why you should keep it on a scale 240 volts or higher.

It used a simple glass fuse that I had at home, or that can be bought at any Radio Shack or auto parts store.

BTW, what I did at this point is to push on the center, with an all-WOOD thing, a DRY thing, a long dry thing, like a dry stick or a chopstick, on the plastic, and if you push down almost a half inch, when you hit bottom, the AC compressor (and fan) will start. If the only problem is in the thermostat/24 volt circuit, and the AC circuit breaker is on.
I only ran it this way for a second or two. There is no rush except if the fan is not on in the house, the evaporator inside wwill over-cool. But a second is plenty time, because it says that the problem is that the contactor is not closing.

Well, in theory the contactor could be closing but one pair of contacts could be so bad that you don't get the 220 on the other side. The contactor is a double pole switch. It interrupts both sides of the 220.
When I see an AC in the trash, especially my own brand and model, I take out some of the parts, so I already have a spare contactor for my AC, and another beautiful like new contactor which will work for almost any AC. But I haven't needed one yet. I forget how much they actually cost, but even if it is only 20 dollars, I like having one available at home.

You might have one too if you or a previous owner signed up for that.

I'm not talking about closer along the very same wire, but first on one side of the temp-disconnect, then on the other side, etc. You don't have to remove the insulating connection covers, you can stick the probe in parallel to the wire.
And I wouldn't disconnect anything. Just use the voltmeter part. If you're not near the 220, you can use some AC scale over 24 volts, although my cheap meter, for use out of the house, starts at 200.

The diagram actually indicated there was a switch there, but it was behind something.

All the more important if it is one's own AC. But he might call me again if he has more trbouel someday.

I'm always an optimist, but sometimes I'm right.
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wrote:

My god, child! I wouldnt let you anywhere near my A/C unit. You are scary and very dangerous. Why would you check voltage at the compressor terminals to check if the breaker is "closed"? I wonder what effect that silly contactor would have on that theory? You should stick with what you dont know how to do. Bubba
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wrote:

One has to check if there is 220 inside the condensor unit. One has to check if it is present at the compressor (or the fan, which is for this purpose the same thing) Checking at the compressor also verifies if the breakers are closed.
He said all the breakers were closed, but maybe the AC breaker has failed. It's one thing you have to check, unless you skip that and work on the 24 volts first and find the problme there, as I also suggested.

This was for when contactor is closed. I think that's obvious to you and even the OP. I'm not going to go back and check if that was expicit, but even if perhaps it wasn't, I said at the end that the post wasn't in logical order.

Would I have to tell you that there will only be voltage at a lamp when the lamp is plugged in? I'm sure the OP will understand.
It was good of you to point out something he might have a question about, but I know what I'm doing and don't imagine otherwise.
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wrote:

With that, all I can say is (and I stole this line from someone in here) "sometimes, its just not worth chewing through the restraints" Bubba
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The link was not a good one, can't tell you anything about the system without the rest of the model numbers and serial numbers. Your best bet at this point is to call your local Rheem dealer to come check, service, and repair the system.
BTW, Hunter makes great ceiling fans, but there thermostats are crap.

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Page not found Oops! Looks like you followed a bad link. If you think this is a problem with Flickr
Guess that link won't work. Since the only thing that changed was the thermostat, I'd be tempted to recheck the wiring on the stat.
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The first thing I would suspect is that you did not install the thermostat correctly. Did you test for both heat and ac after you replaced the thermostat?

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