I am replacing a standard radiator on a combi boiler central heating system with a modern reproduction of an old style 4 column radiator. It states that the bleed valve MUST be on the side opposite the feed but most advise I can find states it doesn't matter. I don't know yet which side is which (already removed old one) so I've 50/50 chance of being right but does it really matter and why would they advise this. Thanks.