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Evaporator leak

Posted by langle1033 (My Page) on
Sat, Jun 27, 09 at 19:11

My upstair AC unit stopped blowing cool air. I found a small hole in the evaporator coil.

Can I just repair the leak with the torch and some solder material that I can buy from Home depot?

Thank you

Follow-Up Postings:

RE: Evaporator leak

Yes and no. Yes you might be able to repair the leak with solder stuff you can buy at Home Depot IF it's just a slight rub or pinhole leak provided you use a mapp gas torch and the proper solder. But no, you're air conditioner will never work again. You also need dry nitrogen to purge the system while you're soldering and then to pressurize to make sure you have actually repaired that leak and to make sure there are no other ones. You also have to replace the liquid line drier which "cannot be bought" at Home Depot Then you will need a vacuum pump to evacuate the system. I use a pricey thermister guage myself but we're trying to save a buck here so we won't buy one OK? Then a jug of freon to charge the system 'Properly". So lets see, solder stuff at Home Depot, torch etc. $35 to $50. Also one tank of dry nitrogen, about $16 with tank swap, otherwise about $100 for a new tank. Nitrogen regulator about $265. Refrigeration guages, $50 for cheapies. Vacuum pump, about $350, pump oil,$7.50. 30# jug of 22, paid $225 for one last thursday. Liquid line drier, about $5. Lets see, what else, oh yeah!!! Recovery certification so you can buy the freon, figure another, oh geez who the hell knows how much that rediculous piece of paper that keeps you from paying a $10,000 fine is costing these days. Did I forget anything? So to answer your question, yes and no. Hope this helps. :-)

RE: Evaporator leak

By the time you hit that coil with mapp gas (or acetylene) to get it hot enough to melt silver bearing solder, there won't be any fins left and most likely all of the adjoining solder joints will be melted.

If you were able to fix the leak, the unit would still need to have a dryer, evacuated and recharged requiring special equipment that Mr. HVAC listed. Unless someone punctured the coil with something to cause the hole, I think what you will find is a new leak appearing soon after you fix this one.

This one is for the techs here....I've repaired many a window unit evap. coil, refrigerator evap puncture leaks with Super Poxy over the years. It does work!!!

RE: Evaporator leak

Thank you for your inputs.

Maryland Irisman: can I use somekind of super epoxy instead of solder ? What is the name of epoxy that you talking ?

RE: Evaporator leak

The Super Poxy I am referring to is sold at refrigeration supply houses. You could try JB Weld but you will really have to make sure the spot where the leak is, is totally clean and absolutely clear of any residual oil. The most minute amount will prevent a seal. Cut a small piece of aluminum foil, apply some epoxy and put over the leak and apply some pressure with your finger. Cover the foil and a 1/4 inch area around the foil with epoxy. As the epoxy cures, you need to pull a slight vacuum on the system. Do all of this within 1 minute.

You only get 1 crack at this. If not done properly and successfully, it is unlikely you will be able to remove everything to try again.....good luck

RE: Evaporator leak

langle1033, don't you understand? By you fixing the leak yourself you're air conditioner still won't work! I wasn't trying to make a joke or anything of the sort.

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