Thoughts on mini-split versus central HVAC systems

[Tom M King]

I know someone who used this, and still had a leak on a mini split flare connection. https://www.amazon.com/Refrigeration...008HOSQQQ&th=1

I asked him what kind of wrench he used, and he said an adjustable wrench. I know there is at least one adjustable wrench torque wrench sold for this job, but I don't even trust that.

[Tom M King]

For anyone interested in learning about anything to do with working on these, this is probably as good as any, and better than most such channels on youtube.

https://www.youtube.com/c/acservicetechchannel

[Jim Becker]

One really must take great care when hooking up the line sets, no matter what tools...it's not a good place to rush as just a tiny booger of a thread can make for a bad day.

[mark mcfarlane]

Mitsubishi is doing a great job making air conditioners!

I have to agree Maurice, I have and love a Mitsubishi mini split and a multi-headed cassette based system. The only downside is depending on where you live it may be hard to find someone really manufacturer qualified to work on them. I have a service guy but he lives 45 minutes away. There are a dozen closer service companies.

[Tom M King]

Here's a flare nut socket on a torque wrench. When I was working of a hydraulic system on a tractor, the only way to not distort the line nuts, and thus not have some small leak was to use a flare nut wrench or socket. The mini split flare nuts are thicker than the typical hydraulic line nut, but all the ones I've seen leak were done with a regular, or even worse adjustable wrench. If either side of a flare fitting gets distorted at all, it's going to leak. A Flare Nut Wrench grabs the fitting all around, instead of on just two opposite sides.

A common problem with a hydraulic line on a tractor is someone would have tightened it with regular wrenches, it leaked, so they tightened it some more with regular wrenches which further distorted things and made it leak worse. Picture of twisted line came off that tractor, and was no doubt a result of such a heavy handed mechanic. It was buried under the bottom, and had always leaked since I owned that tractor.


I've never had a leak on any kind of flare fitting when properly tightened with a line wrench (common name for flare nut wrench).