Don't know if anybody else has this problem, however I've been fighting my home air conditioner for several years. It leaks Freon and shouldn't. Trane outdoor units.

For the first few years, I would call the AC guy out and pay him $200 to recharge it. Then I was talking to my Brother in Law, who has an AC license and he came out and did it the next time. System works fine when charged, but leaks the freon out.

Well, I got tired of that, so I got my own AC license, so I could buy the stuff and bought a can of Freon and some gauges. I even bought a leak detector, but couldn't find any leaks around the coils or the compressor.

Well, I finally figured out the source of the leak. It was the stupid Schrader valves and caps. Trane uses solid brass Caps, without O-rings. I stuck some o-rings in the caps and cranked them back down - no leaks. I spent maybe a thousand dollars on a 50 cent problem. I wonder how many other people fight their AC system like this. The repair guy kept telling me I needed a new system - when it ends up the one I've got works perfectly. I wonder how many people fall for that sales line.

I find the AC license is really a license to prey on ignorant consumers (until now me). Don't try to find decent information online either - you'll find nasty contractors telling you you'll ruin the environment - except in my case they were letting the stuff leak until I fixed it.

Anyway, I was clueless about AC prior to this, and I had to learn it, so all was not lost. Rant off.

Wow, great tip. Glad you solved the problem. I've heard valves can be problems in tires, in fact my brother just had a leaky one, but would have never thought about it for an A/C system.

How much did the AC license cost you?

I usually don't have any problems once I tell them what I do for a living.

Dateline or 20/20 had a story like that on bad AC companies charging for bogus repairs.

I stick with Industrial stuff. Indy, you have a reason to be upset it looks like. You could call the AC company up and let them know you fixed THEIR problem.

Seems standard operating procedure for alot of companies to just sell you new units as they lack the skill or desire to repair you current one.

Another case of consumers having to become experts in every conceivable area just to stay alive.

What's involved in getting the license? I've thought for years about becoming AC knowledgeable but never thought about the licensing aspect.

Partially true.

More profit in replacing than repairing. Sometimes it does make more sense to replace. Indyboater's case, however, isn't one of those times.

The so-called experts always preach more profit, more profit. That's ok, but some companies push it too far.

Again, we're not all slime ball crooks. Move on until you find someone honest. They're out there, you just have to find them.

I usually find them, get what is needed and then they go out of business. For example; my central air unit. Looked at a few different ones with a few different companies a couple years back, settled on one I felt was very good and a reputable company in the area. 6 months later they went out of business.

Please let me know your company name if you are in the Detroit area. I promise I won't call any of my BABC friends.

Indyboater

Could you provide a pic of the valve and where it is located? My AC Trane system just quits working over the weekend when we were out of town. The last time the AC guy came out he said I have a slow leak (few months ago) and he recharged it. Now my AC is not putting out cold air, although air is blowing out of the vents. My AC is central system: one part outside and part in the attic.

Thanks

Same as mine. Schrader valves look just like automotive valves on your car tires - just bigger. And they have brass caps on them instead of plastic ones.

They are located on the outdoor unit, on the refrigerant lines that come into and exit the unit.

Assuming your blower is working, It's hot outside, and the outdoor unit is working - the fan is blowing and the compressor is pumping, then it's easy to tell if the system is working. The big refrigerant line should be cold, and the smaller one should be hot to touch. If they're not, then you aren't refrigerating correctly.

You buy a set of AC gauges and hook them up to the schrader valves - the blue hose hooks up to the cold (Low Pressure)line and the red hose hooks up to the hot line (high pressure) - pretty easy. Then you can tell exactly what is going on with the system. It's not rocket science.

Then you buy a can of the correct refrigerant, and you hook the third line(yellow) up to it and recharge the system into the low pressure (cold) side. But you do have to have the gauges and some knowledge in order to do it.

One thing to do, if you have a trane system is take one of the caps off and see if it has an o-ring in it. Also they should be more than finger tight - you need to use a wrench to get them on or off. If it doesn't have them , next time the guy charges it, have him put o-ring caps on it.

Like anything else, it's way more profitable to replace rather than repair. Consumers are conditioned to spend thousands on a new HVAC system - and it's much easier to swallow that than the few hundred here and there nickel and diming you get on maintaining one.

So Indy, you simply added a rubber o-ring to the inside of the valve cap and that did it?! I was thinking you somehow added it to the valve insert. Just wanted to be clear, you didn't have to unscrew the insert of the valve, simply the external cap?

So I guess if you ever have the system emptied for any reason, then you would replace the valve insert. I don't suppose there would be anyway to do that w/o letting all the freon out.

Just for grins, what is the recommended pressure for the low side and high side? I did some work w/ A/C in another life, but don't remember what pressure we considered "normal". Does it vary with the system brand and type these days? My work was at a very large garden style apartment complex that had identical units.

WalMart sells chrome plated brass Shrader caps with rubber seals in them. I use them on all the tires in the family. A 5-pack runs a couple of bucks.

I didn't remove the schrader valve - that would involve either pumping down the system or leaking a bunch of refrigerant (which is illegal).

No I just took out my handy o-ring kit, found one that fit inside the cap, and tightened it down good. Problem solved.

The pressures vary with the ambient temp and the unit itself, however mine (I have two) run about 75-80 on the suction side and 275 on the high side on a hot day.

You actually use these pressures to figure out the superheat of the system in order to determine the charge.

Auto tire Schrader caps are much smaller than HVAC ones. Also my cars have different connections on the R134 AC system than my house, which uses R-22.

I would say at least a rudimentary knowledge of refrigeration is pretty good to have - we all have refrigerators, and freezers and window units and car units and central air - they all work basically the same way.

Here's a page that'll give you some of the basics.

http://www.inspect-ny.com/aircond/aircond1123.htm

you would be surprised as to how many times the "pros" will simply charge a unit and not investigate the reason behind WHY it lost part of a charge especially when there is significant loss.
keep an eye on the valve caps they will start to leak again.

when looking for a leak, start obvious - look for any oil on the condenser coil (outside unit) bubble testing and "sniffers" work great too.

Indy, good job in finding your problem!! take this with a grain of salt but dont get to "overconfident" with the EPA license. there are alot of things that could go bad in a split system. Guages and beginner knowledge is great to have but STOP if you are unsure about anything.
I speak from 'spierience here - I am NO expert by any means and I will never claim to know more then someone who has been in the field for years.

just throwing it out there.

Timely topic.. my unit went kaput (So I thought) Sunday.. turned it on and it sounded like a stuck pig squealing! I thought the motor in the compressor was shot, so we turned it off and pretty much suffered all day...
Had a guy come out yesterday... I turned it on, and of course, the motor just purred!! It does run hot tho.

So he hooks up his gauges and about falls over! They were running about 200-250 on one gauge and about 375-400 on the other. That's what the guy said anyway. He let some freon out until the gauges read like Indy's post above..He said he's surprised the unit hasn't blown out by now. Too much pressure bad for compressor?! I left it on for the rest of the afternoon but it was too late to do any good. The house never cooled below 85.
He didn't try and sell me another unit, but I am under the recommended tonnage. The unit I have is 3.5 tons and the house is about 2000 s/f. He recommended a 5 ton unit... What is the correct tonnage for a house that size?

So just now (after starting to read this topic) I did a test on the start-up, and sure enough, she squeals for about 10-15 seconds, and as I'm running to turn it off, it stopped squealing and sounded normal! So now I'm really baffled. Why would it squeal? Motor bearing?

Replacement is in the plans for next year, but he said to get it before the end of the year as the EPA is requiring the change to puron in 01/09 and the units will be more expensive. If it'll last just a few more weeks......

All units have to go to 134a or better next year. That shouldn't have a big impact on cost though. the big cost impact was 2 years ago when the mandate from 10SEER to 13 SEER went through.

There are some state EPA's that say when a leak is evident, you must at least identify it. If the leak is in a coil, it is nearly impossible to fix. Schrader valves/caps are always a good place to find leaks. Many of the caps do not have o-rings as they are not there to stop leaks, just prevent dirt. But the schraders do wear out so having the o-rings is a benefit.

As for sizing an A/C unit, there is a lot that goes into it above square footage. But 3.5 tons for 2000 sqft should be adequate unless you have a lot of sun exposure, windows, poor insulation, etc.

WaterMutt, our house is 2 story, with a pretty big attic. I know it's not ventilated adequately, as the temp in there gets absolutely unbearable, even in the winter sunshine, but there is about 3 inches of blown-in insulation. And yes, we have alot of south-westerly facing windows.

When it started getting warm today, I went to turn on the A/C.. I heard the motor running, but couldn't hear the fan turning the air. When I went out to look at it, the motor was on, but the fan was turning very slowly, gathering speed with each revolution, until it suddenly went to full speed... That, to me, would indicate a bearing about to fail. Any suggestions? Is that a repairable item that's worth the cost?

rule of thumb on residential units is about 600sq ft per ton.


the condenser fan motor may be getting ready to fail, or the bearing is failing. either way you dont have a whole lot of time left

what kind of refrigerant is that unit??? those kinds of pressures would be "OK" if its a 410a but if its R-22, at those pressures there might be significant damage caused by slugging of the compressor..

And it's not cooling good either. It's only 90 today, and it's 82 in the house, and the thermostat has been at 74 all day.... Normally, it has to be above 100 outside for it to get this hot inside

How can I tell? The unit is at least 5+ years old, as it's the one that was here when we bought. There was no freon added, that I am aware of, 3 years ago when we had a condensation leak.

The ID plate (not sure if that's what it's called, but it's the metal info tag) is on the back of the unit and hard to get to. Should there be some way to tell on the plate what type of refrigerant is used?

+1.

Indy, how did you find the leak?

I missed all the new posts on this yesterday.

Brady - yeah, I'm pretty well aware of my limitations. I know quite a lot about my systems, but would be lost on something much different.

Nu2 - sounds like a condensor fan motor or bearing going bad - which should be a cheap fix if it's the bearing, but you may end up having to buy a new motor. Note; that fan has nothing to do with the refrigerant or the compressor - it simply blows air over the coils to condense the Refrigerant. Now, its very curious that your pressures would be that high - especially since it wasn't recently charged - and now it's not cooling any more. I personally question whether the guy was reading his gauges correctly and maybe it was charged correctly to begin with and now it's undercharged - since the source of the initial call was the squealing and that has nothing to do with the refrigerant charge. I'd bet the unit is a gibson or a Janitrol brand - they do tend to make a lot of noise. Call somebody else out to check the charge - since the first guy didn't diagnose the fan squeal correctly. 3.5 tons sounds right for 2000 sqft. If it's done OK in the past, it would waste energy to buy a bigger one. There's no reason that a unit shouldn't last way more than 5 years. I'd say 10-15 minimum.

As far as going to the new refrigerants - well, they aren't as good at refrigeration, so the unit sizing, therefore the cost will go up, to get the same amount of cooling. My opinion is the jump to 13 seer was mostly just an excuse for a price hike for everybody in the chain - the actual equipment changes were relatively minor - usually bigger capacity evaporators and inclusion of TXV's.

Finally, about my leak. Well, I wish it would have been more scientific, but it wasn't. The service guy came out and filled it several times over the course of about three years, telling me how much greater a new one would be each time. I had bought the "service Plan", however, so I got a discount on the service and didn't worry about it much.

I called my BIL out and he looked at it and filled it and said their must be a leak. He told me to look for oil/dirt spots all around the condensor and compressor. Then I bought a couple books on AC and started reading, bought some gauges, and got the license and some R-22. I filled it myself a couple times and noticed it leaked down really fast after I did it one time, when I lost one of the caps, and put a plastic one (from the R-22 container) on it. At this point, I had thoroughly looked over everything and thought if it was a leak it must be in the evaporator. So I bought a leak detector and the only place it got any kind of reading was around the uncapped schrader valves. That's when I got the idea it must be the lack of O-rings in the caps - which solved the problem, so far.

My units are now 17 years old. They work perfectly, and they get a real workout in the summer. At this point, I also determined that I have no desire to have new ones until these won't run anymore. If a compressor goes I'll probably replace it alone rather than the whole system.

I learned two things through the process. 1. The "service plan" that I bought was just an excuse for the service company to try to sell me stuff. They didn't do the proper service, which I learned to do myself, and they had no incentive to fix anything. 2. The whole industry is geared toward replacement rather than fix. I'm convinced that most residential guys just don't know how to do repairs. They want to replace the whole system if the compressor goes out. That's like junking your perfectly good car if the transmission goes bad - sure it costs money to fix, but not as much as a whole car.

Many times due to the age of the unit, labor for compressor replacement, it is better to replace the whole condensing unit. I've priced quite a few jobs, and sold many condensing units based on a $300 difference between the two.

There is a pretty big shortage in qualified and experienced HVAC techs. Many are just gas-and-go guys with little understanding of electrical components and really how the units work.

brady and Indy.... thanks for your info..
I checked the mfg tag and the date is 7/91. Of course, this does not tell the date it went into service, but the unit is now 17 years old from mfg date. And it is an R-22 type refrigerant.
The service guy told me that a slow spinning fan will not pull enough heat off the condenser, thereby not allowing the coolant to perform to maximum efficiency. What do I know! Sounds plausible.

In calling around this morning to see about a fan motor swap, I talked to a guy that said it could be the capacitor going, which would be a real cheap fix, and something I could do. Even swapping the motor sounds like something I'm capable of doing. I've been quoted from $285 to $681 for something that doesn't appear too tough! Getting the motor might be the tough part, as I'm not sure where to start there....

From the description, my first thought was bad capacitor. See if the motor itself has a data plate on it, and try to find a cap or a motor that matches those specs and shaft dimensions.

I hear of people all the time who are told they need a new AC because their condenser fan motor went out. That always seemed like a crock to me. Commercial building owners certainly don't replace their entire AC systems every time a component fails. Not really apples to apples, but the idea is the same IMO.

$300 is a fair difference - then it's just a matter of whether the customer has the money or not. I'm sure the entire condensing unit is a much easier and probably more reliable install - but the guy who has the skill to take on the compressor only is the guy I want working on mine.

I think the "gas and go" guys were the ones that forced me to figure it out myself, so they did me a favor.