"Art" wrote in news:FMWdnYmARbs40fzVnZ2dnUVZ snipped-for-privacy@earthlink.com:
Not an HVAC person but when they come around I stick with em like glue (under a house with the bugs or in the 140 degree attic) to learn what I can. They don't mind since they realize I'm not questioning the validity of their work.
On one the freon was slightly low as you say. Maybe a couple of lbs. He had me hold ny hand on the pipe and told me to watch the gauge as he pumped it in and to watch what happens as the last lb goes in. As that last lb was going in, the pipe suddenly got really cold as it should. He said the last lb can make all the difference in the world because that's when the "flash point" was reached.
Just an FYI. Knowledgable HVAC folks feel free to give thumbs up/down on this info or expand on it.