Baxi platinum 33he vibrating banging noise?

Hi,

I have a Baxi Platinum 33he
The boiler has been installed now for 3 yrs just recently I had the filling loop replaced as the non return valve failed apart from that everything great until about 2 weeks ago a very loud vibrating banging noise when heating first starts to warm up and when running a hot bath,
It seems it cant cope when hot tap on full could this be the fan assembly when speed increases with high demand of water