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  1. #14
    Join Date
    Oct 2010
    Location
    Anderson, South Carolina, United States
    Posts
    7,064
    Quote Originally Posted by dwhitcomb View Post
    We had a rep from Lennox in the other day, and any trace elements of Rx-11 in an under warranty compressor will void the warranty.

    He said the engineers now say to use R-22 to flush linesets. Even on 410a systems.
    That rep must be who supplies you with R22 bc there's no way I'm wasting my R22 sweeping line sets, nitrogen is way cheaper.

  2. #15
    Join Date
    Feb 2013
    Location
    Summerville SC
    Posts
    117
    like everyone else said I wouldn't use anything in a system that isn't for the intended use. get some type of flush kit. ive used most brands and pro-flush and rx-11 work well. after flushing into system you will want to purge the lines again with nitrogen to ensure you got all of whatever flush you used out. get a partner outside holding a rag over the lines as you purge them to make sure of whats coming out. if your still getting oil or flush keep holding the nitrogen to it

  3. #16
    Join Date
    Apr 2011
    Posts
    22
    If I had to use anything other than RX-11, I think I would choose mineral spirits. Isn't mineral spirits a more pure solvent?

    However, mineral spirits is also very flammable.

    It would take a pretty good reason to using either thinnner or mineral spirits - maybe a really large system.

    Compressor manufacturers should indeed get pissed when a failed compressor comes back having failed because of system debris or RX-11.

    My understanding is that sometimes systems are really foul, but I have not had a lot of problems because of dirt in a system. It may have happened to that an very occasional capilliary tube has gotten plugged from dirt, but more often just restricted from baked in POE oil.

  4. #17
    Join Date
    Sep 2005
    Location
    Atlanta GA area
    Posts
    21,187
    One guy I know uses denatured alcohol (from HD paint department). His theory is it totally evaporates and dries... I suggested to him it probably dries out before it washes away the junk in the lines.

    Personally... unless it is a burnout or green slime (that stuff is nasty), just blow it with N2. Better IMO to leave a little MO in the system... than to put something in the system that could cause damage.

    On the flush with R-22... Sounds like manufacturers trying to avid warranty responsibility. How many folks are gonna waste #'s of R-22 doing a flush. I do not know any of them.
    GA-HVAC-Tech

    Quality work at a fair price with excellent customer service!

    Romans Ch's 5-6-7-8

    2 Chronicles 7:14

  5. #18
    Join Date
    Feb 2013
    Location
    north georiga
    Posts
    598
    i'd like to hear how you would keep the pressure and volume of r-22 high enough to clean the system AND not violate venting laws?

  6. #19
    Join Date
    Feb 2013
    Location
    Summerville SC
    Posts
    117
    Quote Originally Posted by davidj001 View Post
    i'd like to hear how you would keep the pressure and volume of r-22 high enough to clean the system AND not violate venting laws?
    x2

  7. #20
    Join Date
    Oct 2002
    Location
    Lexington, NC
    Posts
    5,144
    You guys that are just purging with nitrogen, what kind of pressure are you purging at? I have a lineset that I cannot remove and am up in the air as to what to do to clean it out. It started out that they wanted us to flush, then said don't flush because it can ruin the wiring insulation in the compressor, then said that up to 5% MO in the system is ok. So I really don't know what we are supposed to do. Whatever I do I am putting the line drier at the indoor unit to protect the txv, but there is one outside too so that is tit for tat.
    The main thing is to keep the main thing the main thing!

    If "the grass is greener on the other side", it likely has been fertilized with Bull$hit!

  8. #21
    Join Date
    Sep 2005
    Location
    Atlanta GA area
    Posts
    21,187
    What I 'try' to do is blow hard enough to push most of the oil out. One can use a little common sense about the way a particular lineset runs and proceed accordingly.

    As to pressure... My N2 regulator is set to a max of 300 PSI... I generally crank it up all the way. Then use the blowgun with the rubber cone on it to seal the entrance of the lineset and let-er-rip. Generally I will use about 500# on the tank gauge on the SL and about half that on the liquid line.

    If it is a VERY long lineset... or if I am concerned there are dips in the lineset... then more N2.
    GA-HVAC-Tech

    Quality work at a fair price with excellent customer service!

    Romans Ch's 5-6-7-8

    2 Chronicles 7:14

  9. #22
    Quote Originally Posted by ga-hvac-tech View Post
    What I 'try' to do is blow hard enough to push most of the oil out. One can use a little common sense about the way a particular lineset runs and proceed accordingly.

    As to pressure... My N2 regulator is set to a max of 300 PSI... I generally crank it up all the way. Then use the blowgun with the rubber cone on it to seal the entrance of the lineset and let-er-rip. Generally I will use about 500# on the tank gauge on the SL and about half that on the liquid line.

    If it is a VERY long lineset... or if I am concerned there are dips in the lineset... then more N2.
    At 500PSIG you are exceeding the test press of the evap...aren't you worried you'll blow the evap?

    R22 was used for years as flushing agent...Until the Montreal Protocol went into effect.

  10. #23
    Join Date
    Sep 2005
    Location
    Atlanta GA area
    Posts
    21,187
    Quote Originally Posted by hvac5646 View Post
    At 500PSIG you are exceeding the test press of the evap...aren't you worried you'll blow the evap?

    R22 was used for years as flushing agent...Until the Montreal Protocol went into effect.
    Obviously there is a perception problem here... or a troll.

    Read my post again and tell me what I said.
    GA-HVAC-Tech

    Quality work at a fair price with excellent customer service!

    Romans Ch's 5-6-7-8

    2 Chronicles 7:14

  11. #24
    Join Date
    Feb 2013
    Location
    north georiga
    Posts
    598
    i've been using the rx-11 for awhile now with no problems so far.

  12. #25
    Join Date
    Dec 2005
    Location
    Cincinnati, Oh
    Posts
    5,047
    Quote Originally Posted by davidj001 View Post
    i'd like to hear how you would keep the pressure and volume of r-22 high enough to clean the system AND not violate venting laws?
    A few years ago someone posted the specific instructions from armstrong about how to purge an evaporator coil and lineset using r-22.

    It involves a tank of r-22, hoses, a recovery machine, and a recovery tank. Dump r-22 in one side, suck it out the other.

    Or, as I dubbed it back then:
    "The honkeytonk horse**** method"
    "Better tell the sandman to stay away, because we're gonna be workin on this one all night."

    "Dude, you need more than 2 wires to a condenser to run a 2 stage heatpump."

    "Just get it done son."

    Dad adjusted

  13. #26
    Quote Originally Posted by ga-hvac-tech View Post
    Obviously there is a perception problem here... or a troll.

    Read my post again and tell me what I said.
    you said: Quote Originally Posted by ga-hvac-tech View Post
    What I 'try' to do is blow hard enough to push most of the oil out. One can use a little common sense about the way a particular lineset runs and proceed accordingly.

    As to pressure... My N2 regulator is set to a max of 300 PSI... I generally crank it up all the way. Then use the blowgun with the rubber cone on it to seal the entrance of the lineset and let-er-rip. Generally I will use about 500# on the tank gauge on the SL and about half that on the liquid line.



    If it is a VERY long lineset... or if I am concerned there are dips in the lineset... then more N2.
    END QUOTE.

    If you are cutting the evap our of the suction line than there would be no damage.

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