My radiators heat up only at the top of the radoator and does not heat up evenly at the botttom. I have tried bleeding it different ways and balanceing it, but i cannot shift the air-lock. I have a Britony Combi 80 boiler, and i am running 12 radiators of it, is my boiler capable of running 12 radiators?!

P.Vasta, December 2009