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Old 10-05-09, 01:21 AM   #12
AC_Hacker
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When you pump the unit down, you'll be pulling a vacuum on the lines and the indoor unit. There's a fair amount of volume, and moisture could be there.

The gauge you picture is a bourdon gauge, and its accuracy falls off at the lower end of the gauge. It will tell you that the vacuum pump is working, but it will miss small leaks.

If you are going to let the tech do the pump down, it would probably be best to let him do the line set modification. It shouldn't take him more than 5 minutes to shorten the lines and make the flairs.

If you're gonna do the whole thing yourself, you should get some good tools and good gauges, including a manifold gauge and a micron gauge to test your equipment to make sure that your tools and techniques are all working properly.

You have an investment there, and the years of proper service you should expect from your equipment deserve your careful attention.

I hadn't finished the previous post, I have edited it to contain the info I started to write.

Quote:
Originally Posted by Xringer View Post
Hey, owning a vacuum pump might be useful for other stuff too.
And, like you said, I can always sell it..
I have no plans to let mine go...

Quote:
Originally Posted by Xringer View Post
I just read the manual for the AC only unit (borrowed from work) and it
said to vacuum down the lines to 10 mmHg abs, shut off the pump,
then release some R410A into the lines (for 10 seconds), shut it off
and then do a soap bubble test on all the fittings.

That seems simple enough. Hey, that's the same as the AC/HP model too!

Did you use Ester Oil on the fittings before torquing them?
Please see previous post

Best regards,

-AC_Hacker
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