Mini split leak

[Diesel Dan]

Here are my mini split leaks.
Both evaporator coil leaks, no flare issues.
The first one has a small pin hole that had been getting topped off for some time now, paid $$ for a "professional company" that couldn't find the leak. After I got fed up and system leaked down again I put 400psi of nitrogen on it and started checking flares, because that is what most complain of. Upon pulling the squirrel cage out to check those flares I found an oil sheen in the drain pan and an oil spot in the middle of that evap core. Replaced, recharged and working great. Just over month later, unit 2 stops blowing cold. Of course, it was holiday weekend and wife recently had knee replacement so had to top that off until I could source another coil. That one was a massive leak at an evaporator tube end solder joint.

Details:
Fujitsu 18k dual zone condensing units. One unit runs 7k & 9k wall units. Second unit runs a 9k wall and 9k cassette. Both installed summer '17.

Mitch says, 2 outta 3 times but I have to wonder when/if #3 checks out.
OEM cores no longer available because 410a.

 

[bluedog225]

My impression is the guys soldering or braising these joints are not NASA factory technicians. And they’re not working in a ISO 9000 environment.

And the companies that sell these things have multiple suppliers. So it’s hard to tell what you’re getting no matter who you buy it from. Maybe the super high-end ones have better weld quality standards and quality management.

This kind of makes them disposable products that just die when they spring a leak.

Or maybe it’s worth it to go back and fix the factory connections and recharge the whole thing. But I would think if a couple of joints were failing the same guy welded everything. Weld, braze, solder, whatever. Maybe he was running low on flux that day.

 

[Diesel Dan]

My impression is the guys soldering or braising these joints are not NASA factory technicians. And they’re not working in a ISO 9000 environment.

And the companies that sell these things have multiple suppliers. So it’s hard to tell what you’re getting no matter who you buy it from. Maybe the super high-end ones have better weld quality standards and quality management.

This kind of makes them disposable products that just die when they spring a leak.

Or maybe it’s worth it to go back and fix the factory connections and recharge the whole thing. But I would think if a couple of joints were failing the same guy welded everything. Weld, braze, solder, whatever. Maybe he was running low on flux that day.

With the amount of corrosion because the tube spacer plates are steel and rust...not worth the risk. New evaporator core is only $280 OTD.