my boiler shows only 2 neon lites on pcb and the fan will not kick in
I fear its the fan assembly unit as there is 240v to it. could anyone advise please if it could be another problem
If you have 240v to the fan; but the fan is not spinning then it's the fan that is at fault.
You can jump start these by using a long (8") screwdriver and "flicking" the edge of the outer impellor... This might get you heating for a couple of days - But new fan req'd.