Replacing circa 1993 Lennox Gas-package AC unit. HELP!

[sanzan]

No major problems prior. We have replaced the capacitor once before.

After lots of brownouts and blackouts during the recent storm, capacitor fried on July 4th. Replaced it. Wouldn't start. Husband banged on unit with rubber mallet and it started. So, we're okay now but on borrowed time.

Tech who came out has given us a price on a TempStar and a Goodman. He does a lot of commercial work, and its known to us as reputable. Looks like about $3400 for TempStar 13 Seer 3-ton and a bit less for Goodman. I found a chart comparing all the TempStar units, and it looks like they come 13, 14, 15 Seer. Mainline is better than performance line, with mainline having a tin-coated copper coil with 5 year no-fuss warrantly, I believe.

I'm asking for product numbers to better compare. After research, I think I'd rather have a higher-end TempAir or other unit that can take generic parts, than a low-end Trane or other brand name with proprietary part replacement. I can't get specific model number of what I have because the darling techs who installed the unit for the previous 90 year old owner removed them in every single spot. LOL...I will try to call the people Monday and get their records on it. Coastal Air Conditioning is NOT a bidder for my business, needless to say.

Thoughts? Advice? This will probably be done next week. And, by the way, when I called around for estimates, others came in between 3,000 dollars and 6400 dollars (for Dave Lennox special 15 SEER) but all quoted brand names -- Carrier, Lennox, etc. I suspect low-end, and I got prices for 13-15 SEER. Is it worth the money to go for 15 SEER? I know I'll be saving a lot over a nearly 20 year old unit,whose SEER I don't know (bought house 15 years ago). May electricity bill was $250 and June bill was $450, because it is really hot here in Savannah!

Can anybody guess a Seer on this 1993 or so unit?

[RegUS_PatOff]

... Husband banged on unit with rubber mallet and it started.

the Compressor wouldn't start, but the outdoor Fan runs OK ?

OR neither worked without the banging ?

[sanzan]

Fan ran fine, but compressor wouldn't start, even after the fried capacitor was replaced. Banging made it (compressor) start. It's been working like a champ for four days now, and it's even hotter temperatures outside. I don't know how, but these frequent power outages (successive and often) during the summer storms (over 120 heat index here) may have caused it to shut off, because it didn't come on the last time the power "blinked". Could he have made some wire make contact by the banging?

Do you agree we need to replace the unit? It's around 19 years old, I think, but it works great, normally. It's just that I worry what will happen the next time we have an outage, and if banging will work then. Thanks for the reply.

[RegUS_PatOff]

I'm not an expert, and I haven't checked the wiring diagram for that model, yet,

(model number ?)

but it may just be a bad / corroded contact on the Contactor Relay .

If it won't start again, try tapping the Relay, maybe with a screwdriver handle..

[sanzan]

Sorry, I don't have a model number, unless you can tell me another place to look. As I said CAC installed this and removed the model number on the unit and the compressor. ( But, I know they have it on their computer under the embedded base data, because I had to get information from them once before and purchased a capacitor for it. I can get that number on Monday, I think.

Between 4th of July and dear husband's birthday yesterday, we've been busy. We were very lucky that a man who works with my husband could come over to troubleshoot on the 4th, and he is my first choice for the new unit. TempStar is in all the city of Savannah properties, and it works great for them, so he quoted us TempStar and Goodman (2nd choice) with which he is very familiar. Had a new Trane 20 years ago, new install, and it was a disaster. Never again. Prefer one with generic parts. Opinions? Do you think we need to replace NOW or chance waiting until fall? Any ideas about Seer of a near 20-year old unit, so I can compare and choose between 13, 14, 15 SEER?

Thanks.

[sanzan]

Husband said he checked all the connections he could see, as did the tech/coworker. Tech laughed really hard when Jim said, "Well, I can't break it anymore than it's already broken," and started banging on it, and darn if that compressor didn't start right up! Otherwise, it's running perfectly.

I'm caulking and insulating on windows and doors on the south and west sides which face the pasture. That's where the brutal sun comes from, and I'm really surprised this old 3-ton unit cools so well. I'm not going up in size, because we have 1659 heated/cooled square feet, and another couple hundred cooled by window unit (brick and glass laundry porch on the west side). Dogs sleep there, too, in their kennels.

That porch really helps keep down the heat in in the adjoining kitchen. Thinking that I'll go for the most energy-efficient window unit I can find when this one dies. We have storm windows over the vintage windows that the previous owner installed when he built in the 1940s. Beautiful double sets of six-over-six wood windows from even older houses which he searched for when he built this place with his own hands. I plan to re-glaze, caulk, and strip or re-paint the windows. I have put it off due to lead-paint and broken hand issues. Probably do the actual stripping, painting or staining in fall, but I can do some now when the sun is low. I'm adding another dead air space with insulated reflective foil material, followed by heavy curtains.

[jumptrout]

Your existing unit probably about a 10 SEER.

A fifteen SEER or higher can qualify for tax rebates/credits with some cities and the feds.

Usually not enough rebate/credit to compensate for the higher cost of a higher SEER.

As RegUsPatOff suggested.the contactor is probaly very worn and should be replaced.

It is a generic part.

If the compressor was banged,I would inspect the wires and terminals on the compressor for loose or worn connections.

[sanzan]

As RegUsPatOff suggested.the contactor is probaly very worn and should be replaced.

It is a generic part.

If the compressor was banged,I would inspect the wires and terminals on the compressor for loose or worn connections.

Thank you. Jim and the tech already looked, but I think I might take a look myself, with a magnifying glass. I also appreciate your insight into the SEER situation.

[Bullstok]

An alternative possibility: If capacitor was bad, the compressor could have overheated and tripped the internal thermal overload. It could cool off and try to start, then overheat. Repeat cycle. They do not always trip the circuit breaker when this happens. If it feels hot to the touch then checking for a open (no resistance) between any of the 3 pairs of wires could give the answer. As for the hammering: it may have cooled enough to almost reset that last time and the banging caused the thermal to completely close (ie. work). Checking for high amp draw should tell a going bad compressor. It should have its own rating plate for its specs.

Edited July 10, 2012 by Bullstok

[sanzan]

Well, the AC has been working great since husband banged the outside. The Lennox dealer came by to look. He was not the dealer who installed it (that dealer has recently been purchased and has yet to put the old database of customers into their system). Lennox man says it looks like a GCS16r, with a SEER of about 8. Some went up to 10. He's not positive, as it lacks the scroll compressor of the ones we found information on, circa 1998 and 2002. Drat those installers who remove the identifying information!

This dealer seems to think a seer of 13 or 14 on a new gas pack is plenty, because my old house is not air-tight, and we're in the process of reglazing windows. He's sending somebody over to look at ductwork, as it seemed a bit cool under the house. I explained that with our financial situation, ductwork we could pay for would be minimal. I it will be teenager and me under there with foil tape, and double reflective insulation made to wrap and tap around the ductwork, otherwise. College tuition and being out of work for two years has trashed our budget. We'll be borrowing to pay for this. Any tips or observations? Oh, and the Lennox man has guessed that the contact problem is likely inside the condenser unit, which is why the banging worked.