Further to the question on rads taking hours ton reach full heat A new pump was fitted 2/3 months ago. Is it possible that a faulty PCB would cause a fault like this? Is the PCB straight forward to replace? And are they expensive?

DnA, September 2009

the older circuit boards on these boiler are notoriously bad for intermittent faults. you can't replace it yourself though as it comes as a kit where you need to replace the wiring to all of the components in the combustion chamber - fan, stats, ignition etc. job for a pro.

Ian, September 2009