They need to FIND the leak. Replacing the coil without determining if the leak is there would be senseless. Could be a small leak at one of the braze joints outside, could be a leaking shraeder core, etc. Start by having them find the leak, or find another company that will.

I would say make an attempt to find out what seer your existing unit is or approximately and the cost of replacing the system vs repairing. Do not forget to calculate any and all tax credits and rebates into the equation. If you plan to live there for years to come also or 3-5 years is another factor to consider.

Thanks. I am hoping for the best, but preparing for the worst...

Can anybody recommend a reputable AC company in Northern VA/DC area who will try to FIND the problem instead of suggesting to replace pieces one by one until the problem is solved?

Also, how to find out the SEER number of my unit?

vlrok

I would contact forum member maryland_irisman. I believe he covers Northern Va/DC area and if he can't help you, perhaps he can make a referral. his email is listed in his profile.

Good Luck!

I went to the units to check model numbers. Here is what I have:

Outdoor AC unit: Carrier 38TXA042330 (installed sometimes in between 2003 and 2004)

Indoor gas furnace: Carrier 58CVA110-20 (installed separately, 12/2005, after older furnace board fried/burned.)

Looks like AC is rated at 13 SEER. Is it good? (The house it is cooling is 2 story+ unfinished basement, ~3100 sq ft.)

If I want to upgrade AC, do I need to stay with Carrier so that my furnace and AC work "in harmony"? What other (better, more efficient) brands/models would work well with my furnace? What is a good SEER number for my type of house nowadays?

13 SEER was the standard, if not a bit better, a few years ago. Now it's more like 14 or 15.

To me, 8 years isn't that old. Thats less that half its lifetime. Was there a warranty?

if you replace the outside unit, you *may* need to replace the indoor coil in order to match the outdoor unit.

I am an air conditioning tech in Miami, first to your main concern:
Do not replace THE UNIT based on the poor service/troubleshooting given by the first technician, there are tools and technics to find where the leak is like for example an ELECTRONIC LEAK DETECTOR that every ac tech sould always have at hand, and if the leak is tiny you can perform a UV LIGHT-GLOWING DYE TEST that will point to the leak with 100% accuracy, car mechanics do this as well for the ac in your car, some tech will tell you that the likely place for the leak is in the condenser coil for two reasons:
1. It is so expensive to replace the coil that it makes it easier for them to sell you the condenser
2. It is easier and faster (more profitable) for them to replace a condenser that it is to replace a furnace
So find a company that compromises to perform a troubleshooting of your system and offers you at least 03 month warranty if they say the problem is fixed.
It is important to do so because the leak could be in the furnace coil and if so it is under the 05 years Carrier warranty and you just have to pay labor, or it cold be in the line connecting both units and replacing the condenser won't fix it.

If at the end you replace the condenser, what you need is a 3.5 ton condenser (acording to the model number), that is the cooling capacity of your current condenser and you should keep it, don't need to be Carrier, Goodman or Rheem should work just fine (90% of condensers share the same compressor wich is Coppeland)

If you want a higher efficiency you need to replace both indoor and outdoor units and to take advantage of the tax credit you need a 16 seer efficiency system wich every major brand now achieves

I dont know of companies out there but make sure they are licenced, that way if you are not happy you can file a complain to the local Building Department of your city and you will see how fast the contractor is willing to "help you"

Thanks all! I am learning a lot.

The reason I am thinking it is coil that is leaking is because the AC guy who performed initial diagnostic last Spring used some kind of a device which looked to me like "electronic leak detector", according to the posted description. At this time, I don't have a reason to believe he did a bad job last year. He poked his instrument in different places. One of the places that (according to him) showed the "leak" was the coil (which was, by the way, located inside the furnace cabinet in the basement, not outside.)

The reason I am not completely sure about the diagnostic is the following. He said that according to his instrument's reading the leak was pretty minor. That's probably why he recommended simply recharging puron. However, the puron he put back into the system apparently leaked out over the course of last summer. So maybe the leak at the coil was not so minor in the first place? Or it could be because there was more than one place where the system has a leak?

Anyway, I am going to call a different company this time. Based on the info I have so far, the coil might be only part of the problem. That's why I try to keep an open mind and consider alternatives.

Yes, I read that 16 SEER is a minimum rating to qualify for tax credit. My concern is that I already replaced the gas furnace not so long ago. Can I pair my furnace (Carrier 58CVA110-20) with another modern Carrier AC unit of 16 SEER or higher so that they work seamlessly together? If yes, what model would match my Carrier furnace?

If a new (comprehensive) test confirms that the leaking coil is the only problem, how much I should be prepared to spend on fixing it? The company that quoted me the price of ~$1600 last Fall told me that they would have to first evacuate the puron from the system (which is expensive), then replace the coil, and then put another load of puron into the system. That's why it is so expensive, they told me. Does it sound right?

I've seen quotes for complete AC system installs at around $6K. Considering what I have to spend on diagnostics and repairs anyway, plus accounting for $1500 tax credit, I figured I will end up only couple of $thousands short of being able to replace the whole AC system... Or am I missing something and the difference between repairs and replacement is actually a lot more?

"Yes, I read that 16 SEER is a minimum rating to qualify for tax credit. My concern is that I already replaced the gas furnace not so long ago. Can I pair my furnace (Carrier 58CVA110-20) with another modern Carrier AC unit of 16 SEER or higher so that they work seamlessly together? If yes, what model would match my Carrier furnace?"

vlrok

you have a very nice furnace.no need to replace. what type of thermostat? It should be the Infinity controller.

I would add a matching Carrier HP condenser with matching evap coil. Suggestions would be Performance 15 or Performance 16 HP.

I believe you could qualify for tax credit-that would be nice and a big bonus.

IMO
Good Luck!

tigerdunes,

When you say:

"I would add a matching Carrier HP condenser with matching evap coil. Suggestions would be Performance 15 or Performance 16 HP"

do you mean I would only need to replace the condenser and the coil, but not the whole AC unit? What is HP condenser? I am not that proficient in the terminology yet.

vlrok

outside unit is commonly called an AC or HP condenser.

you will need one or the other plus evap coil and this combo with the Infinity 80 furnace must be the qualifying standard for the tax credit.

IMO

I have a similar situation. Our 2400 sq ft 2 story home in NC has 2 a/c units. One has a leak that is getting worse and needs to be serviced several times a year (which gets expensive).

Our units are about 17 years old, so I suspect the repair/replace numbers will lean heavily toward the replacement side of the equation.

The current units are:
Rudd Achiever 10
model # UAKA-024JAS
mfg 10/93 and use R22.

I'm getting some initial numbers together. One service guy wants to quote a 14 SEER unit which I don't think will qualify for the tax credit. OTOH, he says the cost of a unit that does qualify for the tax credit costs more than the credit and a 14 SEER unit will be far more efficient that my existing units.

I'm just starting my homework on this.