Thanks for the help here. My tale of woe concerns my two-and-a-half year old Rheem 2.5 ton 12 SEER heat pump; I take much of the blame for hiring technicians who were doing work on the side to attempt the diagnosing and repair.

A couple of months ago, the AC stopped cooling--plenty of air, but no AC. Technician came out, told me that there were some problems with a piece of wire rattling lose and becoming unsoldered and disattached. All I can tell you about this wire is that it was easily visible and workable down low and to the right inside the removed hood. He fixed this. All was well for a couple of weeks--I returned from a weekend trip to hear the AC sounding as though I had an airplane trying to take off in my back yard. Diagnostician Number One came back out, told me that my reversing valve was now shot, perhaps from remaining pieces of solder or junk from the original disattached / resoldered wire, but he believed that my compressor was still fine. Then the technician's wife ran off with somebody else, leaving him with the kids etc. etc. and he dropped out of the picture, recommending as his replacement the fellow who had "taught him everything" he knows--another independent contractor who does a lot of work for a local HVAC company.

This tech came out, took a quick look at the system and told me that, while I may need other things, he was sure I needed a new compressor to start with. This he ordered under warranty and put in. Didn't need to replace the reversing valve, apparently. Delightful air conditioning for ten days or so. Then...dreadful sounds and again, kaput with the cold. Lots of air, but no cold.

Technician Two comes back out and spends a couple of hours doing tests. Tells me that I need ANOTHER compressor that he is not sure he will be able to obtain under warranty, along with another filter dryer, both TX valves and more flushing. Says that he flushed the unit well when he replaced the compressor the first time. Doesn't know what happened this time around or why. Doesn't want the job anymore. Gas is killing him, etc.

So I decided to take the repaair to an actual HVAC company (what a concept!). They don't know what happened, but managed to get a second compressor and the reversal valve from Rheem under warranty (just fixing the reversal valve for good measure, I think) and recommended that I do go ahead and replace the TX valves (not warrantied) while they are doing the work. They found no filter drier on the system when they went in to do their diagnostics, and will, of course, put one on. (I assume that this is where Technician Two let me down, by not putting in a filter drier when he replaced my compressor, even though he did tell me that he recommended "another" one, after that second compressor failed.)

This HVAC company also suggests I simply think about a new system, in case the acid from the compressor burn-outs has messed up the coils. So...opinions, if any, on how likely the coils are to have been adversely effected? Any opinion on these experiences shortening the life of my whole system?

Repair is estimated at $1600. Upgrading to a 14 SEER 2.5 ton heat pump is $5500-$5800 (Rheem vs American Standard) and to 16 SEER a little over 7K for both.

And, of course, I will never see a penny of what I've already spent. Lesson learned.

Thanks.