I got a tech out to do a leak search on my circa-2000 R-410a system (have
needed 2 recharges this summer) and he detected a leak in the evaporator
coil (he was using some Johnson Controls sniffer).
The coil was labeled with some application labels and one line read
"Refrigerent: R22". I asked the tech about it and he said he didn't think
it was right; after a couple of calls, there was some difference of opinion
among his supervisors about whether it should be replaced at no cost because
it was the wrong part.
One of the tech's supervisors said there's a regulator fitting just in front
of the supply side of the coil that could be swapped out, making the coil
suitable for use with R-410a. Another reference said that this coil was
pressure-tested for R-410a pressures and should be OK (I think the pressure
testing number on the coil label was 450psi).
Is it possible to make a valid case that some corner was cut and an
inappropriate or inferior part was used when the system was installed? Or
are they right and the coil was an acceptable part when installed?
I'm ever-so-slightly out of warranty, and if there's a reasonable argument
to made that a bad/wrong/less-than-durable part was used in place of a more
technically correct or durable part, it'd probably not cost me anything or
just some percentage of the replacement coil price.