polybutylene hydronic tubing

Seems like the Canadian action only covers for replacement and leaks from the acetal joints which apparantly are rare. There is really not much I can do about the infloor tubings since the only way to replace them would be jack hammering the whole house !! Oxygen permeability seems to be the biggest concern. Again, not much I can do about that until the boiler leaks. I wonder if oxygen scavengers/rust inhibitors would help.

I believe that chlorinated water speeded the degradation, and you're not using it in that piping. Could it be that the newer couplers were used in your installation, and that you don't need to be awaiting a failure?

This would help more:

If adding a heat exchanger can solve the rusting problem, are there boilers already with a stainless steel heat exchanger built-in to save space? Also, by using a heat exchanger, then all those by-pass loops and mixing valve can be excluded, correct?

How can one tell if the tubings and the joints are the affected ones? Are there markings on them?

Also, upon further reading on the settlement, the Canadian action was only settled in the province of Ontario. Does anyone know if the other provinces settled, especially in British Columbia?

Problem is the coils in the floor ARE the heat exchange surfaces.

From what I understand, the exchanger will isolate the water from the boiler. The water from the boiler pumps through the exchanger, and the water from the floor pipes also pumps through the exchanger, but only heat exchanges between them inside the exchanger. That way, the boiler will not rust out.