Samsung split AC: Gas leak diagnosis

Mun33b (Mun33b) 2024-10-29 15:02:57 +0500 #1

Salam,

Have a samsung inverter split AC at home. The inner coil leaked and replaced with new oem part with a hefty bill, service done by Samsung. AC worked for less than an hour, enough for technician to go away. Now, on re inspection, says that the 4 way valve of outer unit is leaking. I have taken a pic and have inspected it myself, the line seems to have soot like layering, but its dry. No oil on the line anywhere. Can any expert here take a look at the pic and confirm if it is actually leaking. P.S. no pressure testing is done on the reinspection as the technician had no Nitrogen or refrigerant on hand, just another case of pathetic service.
@Xulfiqar

Xulfiqar (Xulfiqar) 2024-10-29 19:24:55 +0500 #2

Doesnt seem so!

If it were leaking that bad to lose charge within a few hours then you could spot check it with bubbles too.

Mun33b (Mun33b) 2024-10-30 15:35:23 +0500 #3

Btw any explanation for pipes being soot coated? Im done with these stupid techs. Going to buy few basic tools like guage manifold, vaccum pump. Already have flaring tool and brazing torch. Btw is nitrogen sold in small tanks? where should it be procured from in Khi?
Also, have you got any experience with refregerant leak detector tools? Worth enough to invest in it?

Xulfiqar (Xulfiqar) 2024-10-30 19:43:49 +0500 #4

no idea, is this soot actually burnt up material or just dust?

you can get small nitrogen tanks too, ask a gas selling place. And yes leak detectors are a good thing, but dont rely on them 100%, do your checks with atleast one more instrument (even a pressure decay test with nitrogen)

Mun33b (Mun33b) 2024-11-01 15:01:19 +0500 #5

Its black in colour. 2 pipes have it and the other 2 dont have it. Also, the inside of line set is not black, rather dull copper. is there any coating of any sort done on the pipes?
I suspect that the 2 pipes which have the soot on them are the heat lines and maybe have burnt up whatever coating was present on them.

Xulfiqar (Xulfiqar) 2024-11-01 19:20:02 +0500 #6

If that was the heater reversal valve then it maybe the cheap coating.

btw, a dull copper coating in the pipes is due to contamination in the system which reacts acidic and proceeds to electroplate stuff elsewhere and makes holes in the original copper piece its leeching from.

installer needs a boot therapy.

Mun33b (Mun33b) 2024-11-02 12:34:19 +0500 #7

Yes the installer is the main culprit, lineset was not vaccumed at installation. The service center wants to lift the unit to pressure test at their so called lab.
Im concerned if they will completely ruin it altogether.