Ugh! Poked a hole in central A/C coil......solutions?

[clattin]

Soooooo.......just as I was patting myself on the back from replacing the dual run capacitor that was bad (see other thread), my obsessive-compulsive disorder took over and I thought I should put just ONE more sheet metal screw into the flange that holds the cover onto the compressor.  but..........that would require me to pre-drill a hole.  Well, you can probably guess what happened.....I didn't pay any attention to where I was drilling the hole and I just hit the top of the coil with my bit and it created a hole and let all the coolant out.

 

Is this something that can be "patched" or am I looking at a whole new coil?  I'm assuming I'll have to have a service guy come out to recharge the system?

 

Dang...........was so pleased with my $15 repair that is now likely going to cost me much more.

 

Thanks!

Chris

 

[BryanS]

A good technician could probably braze that hole closed for you since it apoears to be copper. They would have to cut away some of those fins and it probably won't be cheap. Cheaper than a new outside unit though.

There are epoxies available too, but getting it brazed closed would be best. A technician will need to vacuum the system down and recharge properly.

Edited July 30, 2015 by BryanS

[ACtechGUY]

Wow through the top too!!  Don't worry this is easily repaired with a little silver solder. the whole job should take no More than 2 - 21/2 hours .

 However , If this is a R-22 system.............. It WILL cost hundreds and hundreds to refill. R-22 is going for (at minimum ) , $60 a pound( price depends on you area and the contractor) .  The least amount of refrigerant in a typical system is around 6 lbs. However it could be as high as 18-20 or so depending on line size and distance.

 

If it is a R22 system, I would seriously consider investing the cash you would have spent on R-22 refill  into a new 410a system.

 

Good luck !

[alamo1718]

Ditto the other replies, brazing some silver solder onto that wouldn't be to hard. You will lose some of the aluminum fins, they burn off with the heat of the torch, therefore some cooling capacity of the coil. Cover the hole until it gets fixed to minimize the amount of moisture that gets in the system. There are epoxies I have seen, I carry one, but haven't used it yet so I can't speak to it's effectiveness. I'll look in the morning and post the name of the product.

 

On the side of the outdoor unit is the amount of R22 installed at the factory when the unit was installed. It will be listed in ounces. This is the correct amount for proper operation with 15 feet of line set. That is the minimum amount of R22 you will need after the repair, unless the indoor and outdoor unit are less than 15 feet apart. Ask your tech how much they charge for R22. That might give you a on the phone idea of the starting cost.  

 

 

[clattin]

What kind of solder should I use?

 

I'm guessing I should cut some of the fins off so that I can get good access and clean the area really well, flux it good and then use a thick solder so that it doesn't run down into the hole?

[alamo1718]

15% Silver solder and an Oxy Acetylene torch set. Anything cooler burning would take to long, i.e. Mapp, acetylene only, or propane. I have never used flux with silver solder, it doesn't need it,  but there are special mixes with higher silver contents that have a flux coating. They are expensive and I can only find them at HVAC supply houses but they work great. They would be overkill in this situation in my humble opinion.  I just clean the area well, rough it with some sandpaper or small wire brushes. 

It is industry standard to flow Nitrogen through the lines during brazing to prevent oxidation of the interior of the lines. Low pressure, 1-2psi. In theory, this would help the sliver solder not fall into the hole also. 

I would suggest drilling some holes in some copper pipe and practicing several times before trying this on the system itself. The key is heat control, too hot and you blow another hole in the pipe and too cold and the solder won't melt. I would think the other key would be using just enough to fill the hole and no more. 

Can you turn the coil upside down while it gets brazed?

[ACtechGUY]

Don't do it yourself. Seriously. Patching a hole in a condenser is easy money for a GOOD experienced tech. But you are not experienced and WILL melt the thin thin thin condenser tube. it is easily half the thickness of a standard 3/8 inch tube.  It is beyond easy to melt that tube into something unrepairable. I've seen many techs never really master patching a hole like that in such a thin pipe. These are guys who can successfully braise regular copper pipes, yet they will still melt the pipe trying to patch a hole in thin pipe. VERY delicate work.  

 

Now if you can get ahold of old condenser coil pipe and practice practice practice on that...  go for it .