Help my A/C (home ) went out again!

[guitarbug]

I posted about a month ago about my A/C going out , well its not blowing cold again. Does anyone here do A/C work ? I think it may be just low on freon, the pipes comming off the unit are a little cold twich I think means my compressor is still working. The fan is running, but just does not seem to be cooling. Please contact me if you know anything about A/C or anyone trustworthy. I have had some bad exsperiences in the past and need a honest opinion. 817-416-0305 Chris! I live in N. Richland Hills

[DJ.]

I'm just waiting on mine to go at an minute. This is the second summer that it has been making a very loud ratcheting noise as it winds down after it shuts off. I checked into it and the AC guy says there is nothing that can be done about it. So I am waiting to spend $2K+ on a new system instead of on a new lens or body.

[Hanky]

Are your pipes frozen? Check outside the line from the compressor.
If so shut it down for about three hours and if they are frozen rigourous filter replacement will help.(minimum replace once a month). I'm afraid I do not have any references for you however.

[guitarbug]

Yea, I hear you Dave. I know I need a whole new unit, but I am trying to buy a little time with this unit until next year at least.

[guitarbug]

Henry, the pipes are not frozen, but the one that is suppose to be cold is! But its not cold enough I believe. I think its suppose to actualy be a lot colder. Its telling me that my compressor is working but not enough freon. Thats my uneducated guess.

[kenw]

your smaller pipe coming out of the outside unit shoud be cold enough to sweat (condense water on the outer surfaces). It also should be insulated so seeing the sweat may be difficult. More importantly, it should be sweating where it goes INTO the inside coil.

If it is sweating as it exits the outside unit, but not as it enters the inside unit (near the fan, in the attic or a closet), then you are definetly low on freon.

IF you had it filled with freon and it is now low again, you have a leak somewhere. The most common place for leaks is the coil inside, it corrodes over time. You could easily have it replaced and keep the outside half for now, splitting the cost over time.

There really isn't a good short-term fix as freon gets expensive if you have to add it that often.

[epoh]

My BIL does A/C repair, but I'm not positive he works that far out (he's in far west Ft Worth.) I'll ask him next time I talk to him.

[my3peas]

We just had to have our evaporator coil replaced. AC was working 24 hrs and it had a slow leak. Just as they were finishing up working on the inside, and ready to begin putting freon in the compressor, the tech pulled off the dryer and some bits went into the line. *sigh* There went our compressor. :( we were without a/c for 5 days. This was the one instance I was happy for all the rain and cool (though humid) air we've had down here!

[guitarbug]

Thanks Ken & Amy. Sorry to hear that christie thats a bummer! Ken , the bigger pipe is sweating a wee bit on the inside and out, but the smaller one does not seem to be at all. I did a temp reading at the return and its about 83 and at the ceiling vent its about 78, not good I know but does this sound like I still have a working compressor ? I did not have a freon fill the last time someone was here. I am hoping that maybe its just low. One more thing, I hear a little gurgle near my inside vertical unit ? I changed the filter and looked at the coil and it does not look to dirty, do you think it may be clogged and thats the gurgle sound I hear. I do have someone looking at it tomorrow but If I need to contact you after whats the best way ?

[hhscr]

Chris,

The small line shoud not sweat. The larger line is the return line and it is carrying the cold freon vapor this is why it sweats. It is condensing the moisture below the dew point in the ambient air.

As far as the gurgling noise it could be the condensate drain line sucking air through the driain pipe or you could also be hearing the liquid freon flowing through the small line.

From all your description YES you do have a working compressor, but it is possible for the compressor to have internal problems that can cause the system to not cool even with a full charge of freon. The only way to diagnose this is with temp readings, amp readings and PSI readings from the gauge set.

The 5 degrees of temp change is a low reading and should be somewhere around 15 to 16 at min and 20 is a good number. I don't expect you can get 20 but it is something to shoot for.

If you need more info, send me a PM. I do A/C Service Work, NRH is a little far for me but if I can be of any help let me know, and maybe we can work something out.

[guitarbug]

Thanks Darrell, I could treat your home for termites! lol, maybe! Let me see what happens tomorrow and I may be in touch, thanks!

[hhscr]

Don't even say the work Termite. That is the last thing I want to think about. Probably about as much as you thinking about A/C problems.

I hope low freon is all that is wrong and not a compressor problem, just wanted to let you know that it could be other things. As stated already if you have to keep adding freon then there is a leak and it is usually in the evaporator coil in the house, lots of corrosion is common in coils.

[guitarbug]

I could drop a few termites off in you're yard then you will have some reason to barter with me, lol.

[Roy]

I know where you can drop some termites off.....no wait, nevermind. Hope you get the AC fixed ASAP and that the cost is minumum.

[kenw]

you are defintely low on freon, and yes the compressor is still working. It COULD be damaged (ie; weak) but it doesn't appear to be if you are getting any temperature difference at all. The large return line should NOT sweat much past the inside coil. If it does, it typically means it is overcharged (too much freon) and the expansion process is still happening way beyond the inside coil. The correct way to tell is by pressure, an AC tech will have the gages to measure the pressures.

The expansion process happens where ever it can; in a properly charged system there is just enough to make it to the inside coil and do the expansion there where it will cool the coil. Basically the small pipe should be so full of freon that it can't expand until it reaches the expansion valve right before the inside coil (and usually inside the cabinet) Some will inevitably go a bit beyond, and the exiting large pipe will also be cool enough to sweat a bit. How far depends on the inside temperature, the outside temperature, etc. A few feet beyond the inside coil is normal, but it should never be sweating where it goes back into the compressor.

In a low-freon scenario, all of the expansion will ocur in the small pipe somewhere between the outside unit (compressor) and the inside coil. There's not enough freon to make it all the way in to the inside coil. That's why the small pipe will sweat; it won't if the correct amount of freon is in there. So if you see sweat on the small pipe coming out of the compressor unit, it definitely means you are low on freon. Realize that if you don't see sweat there, it doesn't mean you aren't low on freon, it's just a quick indicator that works in most but not all cases. Again, gages and know-how are really required to see if everythign is ok.


good luck.