Ariston Combi boiler central heating problem?

thanks Ian. I did remember I had a new flowswitch and pcb fitted in june. I got the installers out and they said it is a blockage in one of the boiler components which is unfortunately not covered by my homecare agreement because its a problem with the water rather than a component fault (ye right mate) anyway they offered to perform something called a sonic clean of all components for a cost of £200+ with no guarantee that this will cure my boiler problem. does anybody know of a cheaper and more effective way to clear the blockage in my boiler please.

pete
October 2009

faulty primary flow switch

Ian
October 2009