We had a new Viesmann 100 fitted by qualified Viesmann engineer in 2008, From the word go we had problems with it. We only were given 5 year warranty, NOT 10. In the warranty period we had numerous call outs. At the conclusion we have had in total so far 40 call outs because it kept going wrong. We have 3 filters on it to prevent sludge getting in. Numerous other bits to no avail. Viesmann tell us that the life expectancy is normally only 5 years. They also claimed that the water was sub standard. Our water company soon pointed out they were wrong. Our plumbers state we are the only people who have these problems and think the boiler must have been a Friday one. When they contacted Viesmann on our behalf they were given short thrift and no help. My problem is, I now need a new boiler and they only fit Viesmann.