comparison of spare parts

[FozzieBear]

Can anyone provide a rough comparison for boiler spares between Valliant and Worcester condensing boilers e.g. the things you are most likely to change in your normal day to day callout/servicing business. For example
Circuit boards
Fans
ignition/Gas valves etc
I am trying to decide between a Valliant ecotec (or 800 series) and a Worcester Greenstar 30CDi. I have been offered a 7 year warranty on the latter but have read a lot of bad reviews about things going wrong such as fans and circuit boards. I know some Heating engineers have favourites but a rough rule of thumb will hjelp me make a decision.
Fozzie

 

[Boilerman2]

Unfortunately with so much technology packed into a modern boiler failures are always going to occur, however Vaillant v Worcester, I would go for the Vaillant every time, if only because the Vaillant is easier to maintain, worcesters although easy to install can be a pig to work on afterwards!