This is not normal. Any plumber worth his salt would not have left until all the rads were up to temp. Yes yo can get air in the system for a short while after new rads are fitted, but to have to wait a few days is nonsense. You don't mention if you have a sealed central heating system. Probably you have as you are using a condensing boiler. If your system is sealed you can bleed the rads while the boiler is off, don't forget to repressurise the system after you. This is normally found under the boiler, ( silver flexi hose ),not difficult. If you don't get any joy with plumber you used, get in touch with trading standards.
Ollie
March 2013