Boiler sounds like a vacuum - please help

[SiLarge]

I've had the boiler (Optia) serviced not 3 weeks ago and tonight when I turned it on, the noise coming from it resembled that of a vacuum (normally its just a dull, deep rumble). It begins when the boiler starts but doesn't get quieter as it goes, it stays loud enough to be heard throughout the house. The boiler itself is a condensing model and only 2-3yrs old. Does anyone have idea what may be causing this loud noise? The boiler itself lights up ok and is producing hot water/radiators, it just sounds so very loud all of a sudden and not particularly healthy.
Any suggestions would be much appreciated.
Thanks

 

[Breesey]

Call the man who serviced it back.

 

[SiLarge]

I will but being Bank Holiday and work etc next week, it could be a week before I can get him back and I'm concerned having this noise is damaging something. Plus a week without heatings gonna be cold esp as still got snow here.

 

[Breesey]

The bank holiday may make it difficult to get someone in but beyond that the ball is in your court.
Getting someone in is the only thing that you can do and the only advice you will get regarding this gas appliance - sorry!