So today I called my local HVAC CONtractor out to get me an estimate
on a new startup. While he was over I asked him if he runs nitrogen
while soldering the lines. He said no and claims that you cannot get
the copper hot enough while the N2 is in it.
I called another guy who never showed up. However, I did talk to him
on the phone and he says that he never uses N2 when soldering and has
been doing it that way for 34 years. I thought this was odd since the
manual that came with the air handler specifies "sweep with nitrogen"
and thought that oxidization could be a factor. I didn't mention it.
Maybe oxidization is something recently discovered.
Neither uses Staybrite solder, both claim it will not hold up to the
high pressure. Strange that the high pressure jumped from 200 to 300
between guys (one said 200, the other 300).
My neighbor just laid out $6000 for a new system I priced out at $1400
retail. They had the job done in about three hours. They didn't
even bother to replace the line set, just used the 25 year old
existing one. Same story on the corroded t-stat wire. He has to pay
$125/year to maintain the warranty. What a soaking.