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.