10 replies to this topic

[torchkeeper]

a/c guy did lousy job sweating low pressure line to fitting into a-coil. wondered why he restarted vacumm pump a second time ! OIL and can see a small bubbling pin hole oil comming out. So am I going to lose the charge. Can I pull charge back into condenser and resweat fitting ? buubling as we speak ,what do I do now?
Thanks for the help

[tommytech]

you can pump the refrigerant into condenser coil usually and recover any refrigerant,then try to braze fitting- However, make sure youre not voiding your warranty,if any, by doing so. I would contact that a/c co. to have them repair.

[torchkeeper]

No warranty ,built new house on different location on same property , moved a/c and tappan / nordyne furnace to new home. Had to get a tech to do charging on his own. None of local hvac companies wanted to install my equipment. Furnace only had a couple hundred hours and a/c same. I understand their concern with used units though. Had to install all runs , trunckline ,returns ect. Was refered to guy , he had a couple moments of competence ! Sweat joint look like welding splatter, this unit has the orifices right on a-coil and line set sweated to orifices. Run me through parking refrigerant in condenser. I have a new set of gauges and a new vacumm pump if Ineed it. if i can save it ,I will resweat bad lineset connerction.

[jumptrout]

Just now seeing this. Yes,you will have to vacuum the system after your repair before you release the refrigerant back inside.

[telefunkenu47]

So, are you asking how to recover the refrigerant back into the condenser? Easy...just close off the pressure valve at the condenser unit and run for 20 minutes or so. then shut off the pressure high side valve thus pulling the refrigerant back into the compressor.LG has a pretty good tutorial in their mini split literature as I recall. .Not sure where you would find it, but it is open format and available on the web iI'm pretty sure good luck.

[telefunkenu47]

PS...be sure to triple evacuate the lineset before you open the valves and return the system to service. Some might reccomend trickling nitrogen through the system as you braze the joint to reduce oxidation in the line. Saw a pretty cool youtube video not long ago on this.

[Cactus Bob]

"run for 20 minutes or so" WRONG !!! BIG TIME WRONG !! after this you can replace the compressor . if you run a scroll compressor in a vacuum you will ruin it in just a few seconds . if it's a hermetic it will over heat in 5 mins or less

correct way , even though i never like to do this , sometimes the condenser cannot hold all the freon in the system and i have seen compressors ruined this way ! so be careful !

run system
connect your manafold set
close high side service valve , pressure will not drop for 60 seconds or so and then it drops quick ! , when you get down to right above zero pull disconect .
close low pressure service valve

vent anything left in lines to the air through manafold set

leave manafold set open(to air) when brazing

pull a vacuum on system with pump

turn off manafold set and pump and wait for an hour or so and look for rise in low pressure gauge

if no . turn on service valves and let freon back in , replace disconect and start unit

[telefunkenu47]

thanks bob. I stand corrected.It was late and I was working off of memory.Didnt realize it came down so fast.Are Inverter mini splits any different?This is oil country AC is just coming into fashion up here in the Maine woods, like flush toilets.

[torchkeeper]

Thank you all, one last question. When service valves are closed what does manifold gauges read? Pressure to lineset side or compressor side? I am thinking lineset side or how else would I read vacumm in lineset. Right ro wrong ?

[telefunkenu47]

you are just reading the lineset and A coil, I think. Ill defer to greater minds on this....

[jumptrout]

You will be reading the lineset and Evaporator coli.