Vaillant heating control?

well the worst words used in the boiler/heating industry are "its only a simple job" and this is no exception, i think if i remember rightly that the spindal on those vaillant eco's simple goes throught straight to the pcb and turns a potentiometer which is actualy a part of the pcb so it probably means........a new pcb !

mark the gay boiler man
November 2008