Installer installed undersized radiators

[aplombier]

If that's what you were taught, then the teacher needs to go back to school as he was talking nonsense. Unless, of course, you completely misunderstood what he was saying.

Nothing wrong with old teacher it was my misunderstanding , ive been using computer generated calculations for years now , and have taken them for granted. And forgotton my basics. Suppose I better re enrol on refresher course