What's causing this loud noise from my boiler?

[davidc123]

My Worcester cdi 30 conventional boiler makes this very loud noise frequently, sometimes vibrates the house:


Not sure what's causing it but I've been able to make it happen by having both heating and hot water on at the same time, then turning the room thermostat down so that just the HW is on.

I had a plumber take a look but they've said there are a few things it could be - burner, gas valve, air entrain components, and suggested it might be better to just replace the boiler than replacing things without being sure what the cause is.

So i'm just wondering if anyone here has a more firm view of what could cause this noise?

Thanks

 

[davidc123]

the video doesn't play within the post for me, but works if you click the button at the top right of it