Mini Split re charge questions

4runner1965

New Member
Last week I was checking my perfectly operating mini split and I noticed that when I installed it back in June of last year I left one of the refrigerant pipes a little crooked and I decided that just to bend it a little so I can install the hide line. Well, all of sudden I heard a buzzing noise coming from my connections at the valves in the outside unit. I immediately grabed a screwdriver and removed the cover and tried to adjust it to see if it will stop leaking, I brought a bottle of water with soap to check for leaks and it was still leaking and I tried to tight it a little more and then all of the sudden the whole thing got disconnected and I lost all the refrigerant.

My question is can I go ahead and just charge it thru the 5/16 port with the valves open or closed?. I know it has to be weighted in, my unit uses 700grams of R410a. I have ordered some refrigerant from ebay and a scale to charge by weight.

I have a vacuum pump and micron gauge so I will be doing a deep vacuum, I remember that when I installed it I was able to do a vacuum down to 68 microns. I wonder if you guys can give your recommendations as far as how to re charge it, thank you much for your time. I was suggested by one the old poster here to start a new thread, thank you!!
 

4runner1965

New Member
RXN09NMVJU, Daikin. It needs 1.54lbs of refrigerant. I know how to vacuum the lines but I need to know if I can just charge thru the 5/16 port without any problem since it lost all the refrigerant. I need to know if I need to vacuum with the valves open or closed. I know that it needs to charge by weight and in liquid form. When I charge does the valves needs to be closed or open. Thank you in advance.
 

Merkin Donor

Well-Known Member
Make sure both service ports are open, pull a vacuum and make sure it holds steady below 500 microns for 30 minuets then add refrigerant by weighing in the required amount. Done
 

4runner1965

New Member
Thank you for your recommendation. When the mini split lost all it's refrigerant and when I pull a vacuum does still have any "solid" refrigerant or oil inside the compressor part? So If start pulling a vacuum I won't be vacuuming any solid material or refrigerant oil? Or the refrigerant turns into vapor at room pressure? Thank you.
 
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Merkin Donor

Well-Known Member
Are you assuming there is nothing left refrigerant wise? Normal procedure would be the evac system into a recovery tank, find and fix leaks then pull a good vacuum and recharge. If the system still has refrigerant in it it will be under pressure and you could burn yourself if you aren't careful and ethically we should be recovering any old refrigerant and not dumping it to the atmosphere.
So if it's truly empty fix the leak, pump it down to remove non-condensables and make sure it holds then weight in a fresh charge.
 

4runner1965

New Member
No, all refrigerant was lost and I will follow your recommendation of opening both valves and pull a good vacuum, I did a vacuum a few days ago it held at 741 microns for than an hour. I could not pull to a lower reading I guess my pump is not that good but it held really steady for more than an hour. I will be doing the vacuum again once I get the refrigerant in the mail and will leave it for more than an hour, and then charge by weight in liquid form in a really really slow so it will go inside as a gas so I won't damage the compressor and then fire it up hoping I don't see any error codes, thank you for your help Merkin Donor.
 

4runner1965

New Member
Ok, Merkin Donor. I just finished charging my MS. I bought a postal scale from amazon that weights in grams and pounds. I set it up in kilograms and I charged around 725 grams of freon. My MS is working perfectly right now while I am typing this and its blowing 48 F air. I want to thank you for your good recommendation. The unit uses 700 grams but I put it a little extra because when you disconnect the valve from the 5/16 port it always looses a little freon there. I don't know but I think that my unit is now blowing colder air than before it lost all refrigerant. I had a little trouble with freon purchase from eBay. The eBay seller posted a 7.5-pound tank for 26.99 with free shipping and I ordered it but a few days later it disappeared as a seller. I had to do a dispute with eBay and today I saw that my money was reimbursed. Thank you for your excellent assistance. I was only able to vacuum to 390 microns.
 
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