I'll spare the long details, but I have a Trane heat pump unit (14 seer) which is about 7 years old, installed when we built our house. For as long as I can recall, service guy "topped off" the freon... at the time I didn't realize that really wasn't normal maintenance! I finally got someone this year that did a complete leak search and found the problem.
There is a leak on one of the capilary tubes where it leaves the "TX" valve and splits off to the evap coils. These small capilary tubes are soldered to what looks like a small "distributor" and it's this factory joint that has the leak. He checked everything else and no other leaks besides this one small joint. Besides that, everything is in great shape with the unit.
The tech indicated he wasn't comfortable attempting a repair because it could spring another leak in one of the other factory joints. He said Trane only had a 2 year warranty on the evap coil ( 1999 XL1400 unit ) and recommended that I replace the evap coil ( over $XXX ) or buy a whole new unit.
I'm having a hard time believing that this one leak in one spot isn't worthy of repair / can't be repaired. I'm fairly certain it's always been leaking since it was installed given the history of "topping off" the freon with this unit.
So... looking for some advice on what to do here. It sort of seems like I'm being told to "buy a new car because you have a flat tire". Is it typical to repair something like this in the field given that everything else checks out fine?
Thanks in advance...
(No pricing, due to site rules )
[Edited by jrbenny on 06-16-2006 at 10:29 PM]
A leak from one of the connections in the distributor can be repaired, but since the distributor is brass, it can be a PITA for someone that isn't experienced with soldering copper to brass.
Silver solder and flux has to be used, and a fine touch with the heat. When I do a repair like that, I carefully heat the distributor just enough to remelt the solder in all the joints and hit them all with just a small dab of new solder, so causing other leaks isn't an issue.
Not everybody is comforterable with, or has the tools and materials for doing that kind of work. For something like that, I use a special double torch tip that will heat the distributor up from 2 directions so I can get the whole thing up to temperature without overheating parts of it.
Thanks! What's my best bet for finding someone willing / able to do that type of repair? I assume experience is everything! Also, would they need to evac the lines and re-pressurize after? Actually almost a year ago this one company did evacuate & vacuum test the system (and just put pipe dope on the service port cap to "fix" the leak! Didn't work of course). However, they stood behind their work & sent someone different this year who used a real leak detector to find the trouble spot.
So sounds reasonble for me to think that a repair job makes sense in this case?
Do you have a record of all the times you had it topped off and was it done by a Trane approved Company? My guess is that if so and depending on your state you may be able to take some action with Trane if the condition existed when it was put in. Anyway if you have all the records and you want to take the effort to go up the chain and start with the company that did the install. Try to get to Trane district managers. If you have had Trane peoplen do the maintenance it may help. It is worth a try if the system is not down and out.
Also if you get no help as a last resort (The experts won't like this) there two part epoxy adhesives that hold up well. For an aluminum line there is are acrylic epoxies like 3M DP-820 or DP-805. Plastic Welder II is similiar.
For copper. Look at the DP-270. I have not used it but the specifications look about right.
You may be able to call 3M for a sample. That is is all you need. Or check and auto parts store for a cold welding epoxy suitable for the type of metal. You don't want an aluminum filled epoxy on copper. it will coode and fail. For small pin holes this will work.
Scuff the area fine emery paper to remove the oxidied metal then clean the surface with alcohol or acetone. Apply adhesive over the location of the leak. Wait for the adhesive to fully cure. Then top off the system. It has been done for annoying leaks. I know of a similar problem that was fixed 9 years ago without a loss of R22. There are other adhesives. Many that work with aluimum and few that work with copper because of corrosion issues.
Surface preparation is the most important thing to observe.
Some of the experts may not like this but even if it lasted 10 years it will help. Or as an expert told me recently. "You are lucky to get 15 years out of any heat pump compressor they usually only last 10 years."
mark beiser has the best repair method. just find someone good. And send a ltter to Trane for record.
Pipe dope is not going to do it. But "warning" if you use an adhesive it will be harder to braze later becasue the adhesive must be thoroughly cleaned off.
[Edited by biker128pedal on 06-16-2006 at 10:47 PM]
If the rest of the coil is in great shape, I would repair it, but if the tube sheets of the coil are rusted, I think you would be better off replacing the coil, especially considdering it is a new house.
There is a common problem with evaperator leaks that we have been seeing, with all brands of equipment. One of the causes is from chemicals that off gas from engeneered building products, varnishes, paints, glues, etc., used in the construction of homes, flooring, finishes and furnishings. Since the indoor coil has water condensing on it during cooling operation, these chemicals collect on the coil and form organic acids that eventually eat tiny holes in the copper tubing.
Combine that with the increasingly thinner tubing used in coils to get the high efficiency numbers, and it has become almost normal to find leaking indoor coils in <5 year old houses due to this.
Even if your coil does not have other leaks due to that type of corrosion, it may not be far from it, and those leaks are not repairable.
As for finding someone that is comforterable with repairing the type of leak you have, you could try asking when you call.
Considdering the leak/topoff history of the unit, and that the filter drier is inside the outdoor unit, I would recover all the refrigerant from the system, replace the liquid line filter drier, evacuate the system and recharge with new refrigerant.
I prefere to replace the factory installed driers inside the unit with straight pipe and install a bi-flow filter drier in the liquid line outside of the unit.
Thanks very much for the replies! I feel much more informed now... this forum is great!