a Frozen Boiler?

Hi,
I am now concerned about what damage could be done to a boiler that has been frozen. I am guessing it might be a complete replace if a boiler freezes? Is this correct?

Thanks for any replies

Unless the system was installed with anti-freeze, all sorts of stuff could be broken inside...not good. Antifreeze decreases the heat transfer ability and effectively derates the boiler efficiency, so it shouldn't be used unless necessary.