Would you expect plumber to use push-fit for rad install?

[gasmanstu72]

Personally I prefer compression because plastic fittings can let air in and cause corrosion.

Very early plastic pipes had this issue. I think it was a bigger issue in North America.

I would only use compression fittings where I could see them or were easily accessible.

yes, it was non barrier pipe that caused the problem, if it was on the water main it wouldn't matter.

it should say on the side of the pipe what type it is, but i don't think you can even get non barrier pipe anymore