TLDR: Six years post install, leak in coil, installer says unit not made any more and wants to repair for $3900. Not sure all of this is fair.
Six years after installation the coil started leaking (leak area in picture). It's from AllStyle Coil Company I believe. Original installer at first said non-repairable, so I agreed to replace the coil for $4k (have a 10 year parts warranty, though I see that helped little on the cost since it's mostly labor).
Fast forward and then during install they realize the replacement coil they brought doesn't fit, then they regroup and determine that the model is no longer made and there's no replacement. Now they want to repair for the same cost. I'd have a three-year warranty on labor.
Trying to decide if I should repair, ask for something to be fair, or just put a unit in. Also, while the installer is a reputable company and seem like they're trying to operate in good faith, they've screwed up in multiple ways already so I don't have the utmost confidence.
How likely the repair is to work, and am I at high risk of failure again?
Does it make sense that it's really impossible to get a replacement unit, even from another manufacturer? They're saying the code has changed (new coolant requirement these days)?
If I agree to the repair, should I ask for anything reasonable to protect myself form future failure, beyond the 3 year labor warranty? Seems like I should at least ask for the coolant to be replaced for free if it leaks again within three years (I'm paying $800 for that this time, as part of the total $4k).
Thoughts appreciated!