# coil replacement



## kyhtb

I have a 6 year old, 3 ton Lennox heat pump and the coil is damaged beyond repair. I was told that the coil will cost over $ 800. Can I use a different brand, less expensive, coil? If so, how do I determine if the comperable brand will work? Is there someplace to order discount Lennox parts? Thanks for any and all help.


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## HVAC Doc

First thing I would be asking is what damaged a 6 yr. old coil beyond repair? Many Lennox coils had a 5 yr. warranty so is there any way another Lennox dealer can maybe work with with Lennox to get it under warranty? Have you gotten another opinion(s) to see if the coil is indeed unreparable and has to be replaced? Although it is not necessarily recommended to mix/match equipment types since there is no way to guarantee performance, you *can* mix just know that the wrong match can hamper performance.


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## Lukester

*First thing*

I would like to ask the dealer is how he can replace a coil for just $800. It is not uncommon for a 6 year old coil to leak. Unfortunately the coils manufactured in the last 10 years are not very good. Formicary corrosion is a major problem causing the leaks. If you can get a new coil for $800 then that is a bargain in my opinion.


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## HVAC Doc

Ok, I'll bite. What brand of coil is it not uncommon to leak after 6 yrs.? I want to stay away from them! Seriously, the Amana, Armstrong, Lennox, and Carrier coils we have installed have given us little failure with the exception of about 3 yrs. ago Carrier had a bad run of a particular model of coil which the manufacture replaced. Manufactures could not afford to have failure rates that high especially with all the 10 yr. P&L warranties and/or lawsuits. Formicary corrosion although a problem is not always the cause. It has become an easy scapegoat as to a problem coil rather than a full diagnosis (ie bad solder joint, mishandling, or defect). It is very distinct if a coil does have this issue and I have yet to date been able to find a defective coil that has truely had this problem. For more info on Formicary corrosion, check out http://www.heatcraft.com/resources/formicary.asp


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## Lukester

We have seen all brands with a high failure rate. Carrier and Goodman are probably the highest. We are a Trane dealer and they too have had their problems, maybe not quite as much. We are in the deep south, so I'm sure we would have more problems than some people in cooler climates. Something in the manufacturing process is creating the problem, i.e. recycled(cheap) aluminum & copper, e.p.a. approved chemicals in the galvanizing process. Something is different now than 10years ago. Coils used to last 20 years. We used to never have dirty sock syndrome, even the factory is not sure what causes it, or why some coils produce it and others don't. 

Sorry kyhtb, I know you didn't ask for all this


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## HVAC Doc

One of the fastest cures for DSS is a good treated coil (or if it is installed already) a complete deep saturation and cleaning followed by a good coating with a coil treatment. UV lights also will eliminate DSS as bacteria/mold cannot grow in the presence of UV lights. As for the statement of "the coils manufactured in the last 10 years are not very good" we will just have to agree to disagree as we just are not finding that kind of failure rates here in the midwest.


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## Chuck Meyer

I have 7 of them from a project we did in Florida and that were manufactured by Carrier.


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## baileysair

Here in Florida, indoor coil failures in new constructed homes have become common due to fomicary corrosion. The homes have become tighter due to strict energy codes causing the build up of air contaminants released by construction materials. These contaminates coupled with a high humidity enviroment and air flow are all thats needed for this sort of corrosion to occur.
As for the price to replace your coil, providing your dealer is reputable that is a bargain.
I would not mix brands either it most often ends in disappointment.


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## MechAcc

Here's some articles on Formicary Corrosion we have at another talk site.

Formicary Corrosion 

--------------------------------------------------------------------------------

From Edwin Fine:
http://edwin-fine.com/air_con/formic...formicary.html

From Corrosion Testing Laboratories, Inc:
http://www.corrosionlab.com/papers/f...-1999paper.htm

From Carrier Corp:
http://www.xpedio.carrier.com/idc/gr...-25-041607.pdf
http://www.xpedio.carrier.com/idc/gr...f?SMSESSION=NO


Not all leaks may be from formicary corrosion. Recall that Lennox had an issue at one time where the end plates had been improperly reamed and burrs were left which rubbed holes through the copper tubing.


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## AskForTheSale

kyhtb said:


> I have a 6 year old, 3 ton Lennox *heat pump*
> *Can I use a different brand*


Unless it is a ARI match, NO.


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## moctod

*Formicary Corrosion - Carrier Dual Fuel Package Unit*

Carrier 48XZ 5 ton dual fuel package unit in use less than 3 years. Carrier rep blamed leaking coil on "formicary corrosion". Caused by chemicals in the house??? House is 25 years old. Gimme a break. Blamed short in factory installed wiring harness that was pulled too tight against frame on installing contractor. When you think of Carrier Corp. think of Formicary Corrosion and Extended Warranty.


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## Tinmanfab

If you could, I would stick with the "proper" Lennox replacement.

Ten years ago we were doing coil replacements (NJ) for no less than $900.

I personally had problems with Goodman equipment regarding coils. About 4-5 years ago I installed a bunch of equipment where I have noticed leaks within 3 years of installation. I have replaced indoor coils and full condensers. Goodman is not easy to get along with. Lotta fun changing out a condenser coil. I have not any problems with Unico or York (I am a dealer with them too).


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