"frank1492" wrote in message
...
Are you saying that it is simply illegal for me to these "licensed
trade" items, or that they are simply very difficult. I have done all
kinds of wiring and soldering.


You need an EPA license to buy and to install the refrigerant.

Electric depends on local laws. Some allow you to do your own wiring with a
permit, others do not.

Silver soldering takes more heat than water tubing solder. Contamination of
the lines (lack of, actually) is a big factor in having a dependable system.
Whe I was involved years ago, we ran nitrogen through the coils when they
were brazed.

If control wiring is 48 volts or less, no license is needed.