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  1. #14
    Join Date
    Oct 2005
    Location
    jax fl
    Posts
    84
    yes there is a flare and there is a perfectly good piston in it please read the first one where it states that I did take the piston out and flushed the entire system out with nitrogen. I checked everything and after changing the txv indoor one due to a check valve it still did not work..... No check valve on it...... but now it has me going crazy, cap tubes or rev valve ..... what the hell I have never ran into something like this it has me stumped and I usually dont get stumped on much....
    Sir Ace says, Don't hate the breed, just the breeder!

  2. #15
    Join Date
    Feb 2009
    Location
    Tallahassee, FL
    Posts
    6,048
    Can you blow through the valve with no restriction ?

  3. #16
    Join Date
    Nov 2007
    Location
    Mississippi
    Posts
    1,352
    Did you check the screen at piston in condenser?

  4. #17
    Join Date
    Jul 2007
    Location
    Phoenix, AZ
    Posts
    206
    In heating mode can you check the suction pressure after the reversing valve???? Meaning is there a suction port between the compressor and the reversing valve? That will help you with telling you what is going on with the reversing valve.

  5. #18
    Join Date
    Feb 2009
    Location
    Tallahassee, FL
    Posts
    6,048
    You might just be low on gas.

  6. #19
    Join Date
    Jun 2004
    Location
    Eugene, Oregon
    Posts
    1,018
    I had a similar problem a few years back. Several techs before me tried everything and still could not correct the problem. I put my gauges on and immediately could see there was a restriction. Guys before me pulled the piston and checked it and it appeared fine. I pulled the piston and it wasn't plugged but the orifice looked too small for the size piston. I pulled out my handy drill index to check the piston and sure enough the orifice was too small. It was the correct piston but somehow copper had deposited itself in the piston orifice. I used my drill and chipped out the copper and put the piston back in and it worked great after that.
    You really need to measure the piston orifice to make sure copper hasn't reduced the orifice size through some type of electrolysis. You'll need a drill index that measures orifice sizes.
    "The bitterness of poor quality remains long after the sweetness of low price is forgotten". --Benjamin Franklin
    "Don't argue with an idiot, they will drag you down to their level and beat you with experience". --Mark Twain
    http://www.campbellmechanical.com

  7. #20
    Join Date
    Jul 2009
    Location
    South Carolina
    Posts
    3,230
    Before I did any more to the system I would throw anther pound or two of gas first to see what things looked like. The only reason we hesitate to to throw gas at a system now is because of the cost but it's always a quick and easy way to test a suspected restriction.
    If the outdoor piston looks O.K. then it could also be the screen right before it. On Carriers that piece of 3/8" tube with the flared end that connects to the condenser usually has a screen built in to it. The fact that your pressures were O.K. in the other direction makes that idea less likely but it still is a possibility worth checking.
    Gary
    -----------
    http://www.oceanhvac.com
    An engineer designs what he would never work on.
    A technician works on what he would never design.

  8. #21
    Join Date
    Jan 2005
    Location
    southeast
    Posts
    83
    Throw a sightglass and pressure tap in the liquid line by the condensing unit. The liquid (3/8") service valve is giving low side pressure in heating so you can't tell liquid pressure. I use a electronic sight glass to see if the liquid line is full. Bottom line is there is not enough refrigerant or a restriction in the indoor unit or on the way back to the outdoor unit. You may want to check and see if there is a drier someplace that you havent seen that may be plugged. Suction pressure in heat should have a saturation around 20 degrees below entering outdoor temp.

  9. #22
    Join Date
    Nov 2007
    Location
    Mississippi
    Posts
    1,352
    Quote Originally Posted by air1 View Post
    I had a similar problem a few years back. Several techs before me tried everything and still could not correct the problem. I put my gauges on and immediately could see there was a restriction. Guys before me pulled the piston and checked it and it appeared fine. I pulled the piston and it wasn't plugged but the orifice looked too small for the size piston. I pulled out my handy drill index to check the piston and sure enough the orifice was too small. It was the correct piston but somehow copper had deposited itself in the piston orifice. I used my drill and chipped out the copper and put the piston back in and it worked great after that.
    You really need to measure the piston orifice to make sure copper hasn't reduced the orifice size through some type of electrolysis. You'll need a drill index that measures orifice sizes.
    Where can I get this drill index. That would save me a lot of calling around trying to figure out correct size. I have ran into this problem too (a couple of times).

  10. #23
    Join Date
    May 2009
    Location
    Savannah, Ga/H.H. Island, S.C.
    Posts
    1,492
    At 68 degrees outdoor ambient...you can charge by superheat and subcooling. Charge the system correctly using this method then see where you're at in heat mode. At least then you can rule out the system being undercharged. You have a mismatched system therefore weighing in the charge may not be correct.

  11. #24
    Join Date
    Jun 2011
    Location
    Portsmouth UK
    Posts
    33
    The drill index is (if I am not being a numpty) determined by measuring the piston then checking against a drill index for the correct drill number and trying that drill in the orifice.
    I might be corrected on this
    Martin
    Regards

    Martin

    Portsmouth UK

    Become a friend or fan on Facebook

  12. #25
    Join Date
    Jun 2004
    Location
    Eugene, Oregon
    Posts
    1,018
    [URL=http://www.amazon.com/Drill-Master-Titanium-Nitride-Numbered/dp/B006ZBBW00/ref=sr_1_10?s=hi&ie=UTF8&qid=1356719200&sr=1-10&keywords=numbered+drill+bits[/URL]

    The drill bits are numbered drill bit sizes. They come in handy for verifying orifice size and cleaning out orifices. You can get very tiny sizes to clean pilot burner orifices.
    Last edited by air1; 12-28-2012 at 01:28 PM.
    "The bitterness of poor quality remains long after the sweetness of low price is forgotten". --Benjamin Franklin
    "Don't argue with an idiot, they will drag you down to their level and beat you with experience". --Mark Twain
    http://www.campbellmechanical.com

  13. #26
    Join Date
    Jun 2004
    Location
    Eugene, Oregon
    Posts
    1,018
    Doing a little research online I learned that copper electroplating occurs in a refrigeration system when acids are present. It makes sense because the job that I found copper plating on the piston had the compressor replaced and the piston was the original piston. The copper from the tubing dissolves and is suspended in the oil and usually deposited on steel surfaces in the compressor such as bearings and pistons. The results are that the bearings or pistons will bind causing the compressor to fail.
    Using a numbered drill set you can verify the orifice size. If the drill bit won't fit then you might have copper plating. You should be able to see the plating because the copper is a different color.
    But, if you have copper plating, you probably have acid in the system. Do an acid check and clean-up as necessary.
    "The bitterness of poor quality remains long after the sweetness of low price is forgotten". --Benjamin Franklin
    "Don't argue with an idiot, they will drag you down to their level and beat you with experience". --Mark Twain
    http://www.campbellmechanical.com

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