Extreme noise from boiler

[zsoltimatrix]

Hi guys,

I need some help with this please, we have just moved in to this place and this is driving us crazy:

Every now and again, maybe two three times a night the boiler (or flue) produces an extreme loud rattling noise! It only last for a couple of secconds each time, but it is like the house is comming down!

What could this be?

 

[Dotty]

Something you need to get a gas engineer in to look at.

Job 38.11.