I lost all refrigerant on Daikin MS, please help

pelotin · 03-04-17, 01:12 PM

I recently installed a 9K Daikin MS brand new from craigslists. Everything went fine and it has worked the whole winter and part of last summer. 2 days ago I changed the wires from the disconnect box to the unit because when I wired it back in July/June I did not have the proper wire size I think it was a 14 gauge and I wasn't really happy till I put the 12 gauge 2 days ago. Well this morning I saw that my pipes were not that straight so I tried to give it a little pressure from the top to make them a little straight and installed the PVC thing to cover them, well when I did that then I hear a buzzing noise!!!! and one of the lines started leaking I grabbed a wrench and tried to tight it a little and it kept leaking I put a little more torque and all of sudden the whole pipe got disconnected and all the refrigerant was lost. All I did is just cut the pipe and re do the head and connect it to the unit so no contamminants gets inside. The unit hold 1.54lb or .70 kilograms of refrigerant. Any ideas how to recharge it before calling a HVAC guy? Thank you for your time.

jeff5may · 03-04-17, 09:54 PM

Doh! It's not fun when things don't go your way. Luckily, you were right there watching when it happened. Since the unit was shut down and the fitting was repaired quickly, it is unlikely that any collateral damage was done.

First, you need to figure out what type of refrigerant and oil the unit uses. If the thing uses certain refrigerant types, only an EPA certified person can purchase it. The oil is no problem, all major types of compressor oil can be found locally.

If you can take a picture of the outdoor unit nameplate and post it here, that would be great. Then we will know what you have and what to next. In the meantime, look around on this forum and read a few threads to get an idea of what kind of tools and instruments you need to do the recharge correctly.

NiHaoMike · 03-04-17, 10:07 PM

Pull a vacuum, then weigh in the charge.

pelotin · 03-04-17, 10:16 PM

That's what I am planning on doing. I just need 700 grams of refrigerant and do you think I need to evacuate whatever is left inside the compressor? I have been reading post all over the internet on to properly recharge my mini split and what I have learned so far is to close the 2 valves and then charge by weight the appropriate amount and then pull a vacuum below 500 microns and let it sit for a while to see if holds the vacuum for more than hour if it does not go up to 750 or 800 micros I am good. Thank you for your replies and hopefully, I will get more replies. I called an HVAC guy that installed my first mini split but I did not like that he does not have a scale and he just want to charge it like a regular unit.

jeff5may · 03-04-17, 10:48 PM

If you can pull a deep vacuum on the whole system and then purge with nitrogen while doing a pressure test, this would be best. The flare fittings (and access valves) tend to fail under pressure rather than under vacuum. After pressure testing with good results, then pull another deep vacuum before charging the system by weight. That way, if a flare fitting or anything else goes awry, you don't end up wasting any valuable refrigerant.

Many of these minisplit units, especially the smaller systems, can only be charged by weight if the original charge leaks out. Due to the tiny amount of system charge, they are VERY sensitive to changes in the charge. The closer the actual charge is to the specified amount, the more the unit will behave like it should.

pelotin · 03-04-17, 10:56 PM

It's a Daikin RXN09NMVJU and uses R410. I believe I don't have to have a license to work on my units. I can buy it of off Amazon for 128.00 dollars for 25 lbs. and a scale for 100 dollars, but I don't know how difficult it will be to this. I have a vacuum and a micron gauge that I purchased when I installed it back in June. I was able to vacuum this baby as low as 68 microns I think, thank your help and response.

pelotin · 03-04-17, 10:59 PM

See how my line set it's so crooked so I tried to get it straight this morning and now I am with this dilemma, haha hahaha. My HVAC guy told me that he will charge it for 150.00 but I would like to do it myself to learn just in case I need it in my other 2 MS, thank you again!

jeff5may · 03-04-17, 11:08 PM

You can purchase smaller cylinders of R410a, down to about 1.5 lbs in size. A food or postage scale can be used to weigh in the charge. Both of these together should cost less than $100.

pelotin · 03-04-17, 11:27 PM

Oh wow, I didn't know I could purchase a smaller tank of refrigerant. The only size I have seen on Amazon is 25 Lbs I looked for smaller sizes and see none. Where can I buy one? I will check on a food scale or a postal scale if I get a smaller tank, thank you so much!

jeff5may · 03-05-17, 09:24 AM

OK, I found a 7.5 lb cylinder on eBay.

R 410a 7.5LB cylinder R410a R-410a R 410 Refrigerant New/Sealed HVAC Residential | eBay

27 dollars shipped to your door.

03-04-17, 01:12 PM	#1
pelotin Helper EcoRenovator Join Date: Aug 2016 Location: Riverside, CA Posts: 31 Thanks: 11 Thanked 1 Time in 1 Post	I lost all refrigerant on Daikin MS, please help I recently installed a 9K Daikin MS brand new from craigslists. Everything went fine and it has worked the whole winter and part of last summer. 2 days ago I changed the wires from the disconnect box to the unit because when I wired it back in July/June I did not have the proper wire size I think it was a 14 gauge and I wasn't really happy till I put the 12 gauge 2 days ago. Well this morning I saw that my pipes were not that straight so I tried to give it a little pressure from the top to make them a little straight and installed the PVC thing to cover them, well when I did that then I hear a buzzing noise!!!! and one of the lines started leaking I grabbed a wrench and tried to tight it a little and it kept leaking I put a little more torque and all of sudden the whole pipe got disconnected and all the refrigerant was lost. All I did is just cut the pipe and re do the head and connect it to the unit so no contamminants gets inside. The unit hold 1.54lb or .70 kilograms of refrigerant. Any ideas how to recharge it before calling a HVAC guy? Thank you for your time.

03-04-17, 09:54 PM	#2
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	Doh! It's not fun when things don't go your way. Luckily, you were right there watching when it happened. Since the unit was shut down and the fitting was repaired quickly, it is unlikely that any collateral damage was done. First, you need to figure out what type of refrigerant and oil the unit uses. If the thing uses certain refrigerant types, only an EPA certified person can purchase it. The oil is no problem, all major types of compressor oil can be found locally. If you can take a picture of the outdoor unit nameplate and post it here, that would be great. Then we will know what you have and what to next. In the meantime, look around on this forum and read a few threads to get an idea of what kind of tools and instruments you need to do the recharge correctly. Last edited by jeff5may; 03-04-17 at 10:39 PM..

03-04-17, 10:07 PM	#3
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	Pull a vacuum, then weigh in the charge. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

03-04-17, 10:56 PM	#6
pelotin Helper EcoRenovator Join Date: Aug 2016 Location: Riverside, CA Posts: 31 Thanks: 11 Thanked 1 Time in 1 Post	It's a Daikin RXN09NMVJU and uses R410. I believe I don't have to have a license to work on my units. I can buy it of off Amazon for 128.00 dollars for 25 lbs. and a scale for 100 dollars, but I don't know how difficult it will be to this. I have a vacuum and a micron gauge that I purchased when I installed it back in June. I was able to vacuum this baby as low as 68 microns I think, thank your help and response. Attached Thumbnails

03-05-17, 09:24 AM	#10
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	OK, I found a 7.5 lb cylinder on eBay. R 410a 7.5LB cylinder R410a R-410a R 410 Refrigerant New/Sealed HVAC Residential \| eBay 27 dollars shipped to your door. Last edited by jeff5may; 03-05-17 at 10:38 PM..

03-04-17, 10:16 PM	#4
pelotin Helper EcoRenovator Join Date: Aug 2016 Location: Riverside, CA Posts: 31 Thanks: 11 Thanked 1 Time in 1 Post	That's what I am planning on doing. I just need 700 grams of refrigerant and do you think I need to evacuate whatever is left inside the compressor? I have been reading post all over the internet on to properly recharge my mini split and what I have learned so far is to close the 2 valves and then charge by weight the appropriate amount and then pull a vacuum below 500 microns and let it sit for a while to see if holds the vacuum for more than hour if it does not go up to 750 or 800 micros I am good. Thank you for your replies and hopefully, I will get more replies. I called an HVAC guy that installed my first mini split but I did not like that he does not have a scale and he just want to charge it like a regular unit.

03-04-17, 10:48 PM	#5
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	If you can pull a deep vacuum on the whole system and then purge with nitrogen while doing a pressure test, this would be best. The flare fittings (and access valves) tend to fail under pressure rather than under vacuum. After pressure testing with good results, then pull another deep vacuum before charging the system by weight. That way, if a flare fitting or anything else goes awry, you don't end up wasting any valuable refrigerant. Many of these minisplit units, especially the smaller systems, can only be charged by weight if the original charge leaks out. Due to the tiny amount of system charge, they are VERY sensitive to changes in the charge. The closer the actual charge is to the specified amount, the more the unit will behave like it should.

03-04-17, 10:59 PM	#7
pelotin Helper EcoRenovator Join Date: Aug 2016 Location: Riverside, CA Posts: 31 Thanks: 11 Thanked 1 Time in 1 Post	See how my line set it's so crooked so I tried to get it straight this morning and now I am with this dilemma, haha hahaha. My HVAC guy told me that he will charge it for 150.00 but I would like to do it myself to learn just in case I need it in my other 2 MS, thank you again!

03-04-17, 11:08 PM	#8
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	You can purchase smaller cylinders of R410a, down to about 1.5 lbs in size. A food or postage scale can be used to weigh in the charge. Both of these together should cost less than $100.

03-04-17, 11:27 PM	#9
pelotin Helper EcoRenovator Join Date: Aug 2016 Location: Riverside, CA Posts: 31 Thanks: 11 Thanked 1 Time in 1 Post	Oh wow, I didn't know I could purchase a smaller tank of refrigerant. The only size I have seen on Amazon is 25 Lbs I looked for smaller sizes and see none. Where can I buy one? I will check on a food scale or a postal scale if I get a smaller tank, thank you so much!

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