Gas Central Heating

[trionam]

I have two radiators that wont work they are back to back in the house kitchen/dinning room,I Have tried to bleed them with a key but no air came out they were working fine the night before and its only six weeks since a plumber was checking out all the rads, the boiler is only 5 yrs old,can anyone help havent got the money yet for another call out,all the other radiators in the house are really hot so boiler must be ok!