roll: I have a problem with a leaking air vent on a radiator. It was removed recently (and with difficulty) by a plumber to vent the system to allow him to undertake repairs . I have tried tightening up the plug but it still dripping enough to need a tray to catch it The plumber is on holiday currently, would it be a good idea to get a new plug to replace the old one?Rather concerned that it may be a new rad job???