I like the Jaguar boilers as they are simple and cheap to buy and very reliable.
I am called to fix a few and wish that I could see more as they are a delight to work on.
It sounds as if either the boiler was fitten on a system without powerflushing or you have been seriously overcharged.
You would not say that if you had a Saunier Duval which are really aweful boilers!
Tony Glazier, August 2007