Mini split repair - Page 3

WyrTwister · 07-22-16, 05:05 AM

On both of our MS's , I used an old Craftsman flare tool that I have had 35 - 40 years . I obsessed over the angle , so I did a trial fit . I came to the conclusion , is coated inside and outside with Nylog Blue , the copper tubing is soft enough that that it will conform to the angle of the flare fittings .

The expansion device is inside the outside MS unit . In A/C mode , the refrigerant will flash and cause the line to frost , if given a chance ( low pressure area ) . If you are low on refrigerant , you will have low pressure on the suction side of the system .

Would be best not to run it low on refrigerant . This is my opinion , others may disagree .

A small oil loss is probably not a problem ( a few drops ? ) . The outdoor units come with enough oil for the max allowable line set . How long are your lines , compared to that number ?

I use UV dye on automotive applications . And the little UV flashlight . If in doubt , add a little when you add refrigerant .

Put your gauges on and check the pressures ( after your refrigerant arrives ) . Run it briefly & check to see what the pressure is at the suction side . As long as it has some positive pressure , running , no air / moisture could have gotten into the system .

I would leave it with a few pounds of positive pressure & weigh the amount of refrigerant added , according to factory data . If you can , add it as liquid . R410a is a mix of at least 2 refrigerants of slightly different boiling points . If you add refrigerant as a gas , constantly shake the refrigerant tank to keep the vapor mixed .

Best I remember , you did a self install ? You gained the knowledge base to do a repair , now . :-)

God bless
Wyr

pinballlooking · 07-22-16, 03:22 PM

Thanks. Yes I did my own install with the help and advice of others on this forum.

Good news is I did the repair about 5 weeks ago and it is still running nice and cold.

It really has been put to the test as it has been very hot lately.

jeff5may · 07-23-16, 06:10 AM

I have had good success with the flare tool kits from the local auto parts stores as well. If someone was really not wanting to spend the money on a tool to keep forever, they are available on the "loan-a-tool" program. I believe the deposit is somewhere around $75. Pay deposit, get the set, do the work, return the set for and get your deposit back. Those sets also do the "double flares" which are a little more forgiving and mechanically tougher.

A tip for the less experienced: before you bend the tube, double check that you have the correct flare nut installed. Without it, you will be cutting off that brand new flare and doing it all over again. If you forget, you have my permission to curse loudly.

WyrTwister · 09-07-16, 11:30 AM

I use Nylog Blue on both sides of the flare & nut .

This seems to make it easier for the soft copper tube to conform to the shape of the flare .

God bless
Wyr

Xringer · 09-24-16, 12:55 PM

Just saw a video.. R410A M/S units require 45 degree flares.. Here's the proof!
https://youtu.be/JI1ckYDi2WM?t=53s

I hope!

pinballlooking · 06-18-17, 01:12 PM

My repaired mini split is still running good. I ran across this video that would have helped me trouble shoot my mini split at the time of the issue.

https://www.youtube.com/watch?v=Ds1QiqVx3k0

Just One More · 07-24-17, 02:45 PM

Great thread PBL.... Very good info.

07-22-16, 03:22 PM	#22
pinballlooking Super Moderator Join Date: Jun 2013 Location: SC Posts: 2,923 Thanks: 172 Thanked 564 Times in 463 Posts	Thanks. Yes I did my own install with the help and advice of others on this forum. Good news is I did the repair about 5 weeks ago and it is still running nice and cold. It really has been put to the test as it has been very hot lately. __________________ Current project Aquaponics system , Passive Solar Greenhouse build To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Solar Install 12.5 Kwh- To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Mini Split installs - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. EV Chevy Volt - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

09-24-16, 12:55 PM	#25
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	45 degrees! Just saw a video.. R410A M/S units require 45 degree flares.. Here's the proof! https://youtu.be/JI1ckYDi2WM?t=53s I hope! __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

07-22-16, 05:05 AM	#21
WyrTwister Master EcoRenovator Join Date: Jun 2013 Location: USA Posts: 543 Thanks: 6 Thanked 44 Times in 38 Posts	On both of our MS's , I used an old Craftsman flare tool that I have had 35 - 40 years . I obsessed over the angle , so I did a trial fit . I came to the conclusion , is coated inside and outside with Nylog Blue , the copper tubing is soft enough that that it will conform to the angle of the flare fittings . The expansion device is inside the outside MS unit . In A/C mode , the refrigerant will flash and cause the line to frost , if given a chance ( low pressure area ) . If you are low on refrigerant , you will have low pressure on the suction side of the system . Would be best not to run it low on refrigerant . This is my opinion , others may disagree . A small oil loss is probably not a problem ( a few drops ? ) . The outdoor units come with enough oil for the max allowable line set . How long are your lines , compared to that number ? I use UV dye on automotive applications . And the little UV flashlight . If in doubt , add a little when you add refrigerant . Put your gauges on and check the pressures ( after your refrigerant arrives ) . Run it briefly & check to see what the pressure is at the suction side . As long as it has some positive pressure , running , no air / moisture could have gotten into the system . I would leave it with a few pounds of positive pressure & weigh the amount of refrigerant added , according to factory data . If you can , add it as liquid . R410a is a mix of at least 2 refrigerants of slightly different boiling points . If you add refrigerant as a gas , constantly shake the refrigerant tank to keep the vapor mixed . Best I remember , you did a self install ? You gained the knowledge base to do a repair , now . :-) God bless Wyr

07-23-16, 06:10 AM	#23
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	I have had good success with the flare tool kits from the local auto parts stores as well. If someone was really not wanting to spend the money on a tool to keep forever, they are available on the "loan-a-tool" program. I believe the deposit is somewhere around $75. Pay deposit, get the set, do the work, return the set for and get your deposit back. Those sets also do the "double flares" which are a little more forgiving and mechanically tougher. A tip for the less experienced: before you bend the tube, double check that you have the correct flare nut installed. Without it, you will be cutting off that brand new flare and doing it all over again. If you forget, you have my permission to curse loudly.

09-07-16, 11:30 AM	#24
WyrTwister Master EcoRenovator Join Date: Jun 2013 Location: USA Posts: 543 Thanks: 6 Thanked 44 Times in 38 Posts	I use Nylog Blue on both sides of the flare & nut . This seems to make it easier for the soft copper tube to conform to the shape of the flare . God bless Wyr

07-24-17, 02:45 PM	#27
Just One More Helper EcoRenovator Join Date: Sep 2016 Location: Houston Metro Area Posts: 43 Thanks: 3 Thanked 4 Times in 3 Posts	Great thread PBL.... Very good info.