Hi ,I have a vokera unica 36 he and had a leak from the hose at back of the fan, have sorted leak and boiler works fine except fan runs all the time even when there is no demand also it is starting to get a little noisy, is the fault the fan or could it be the PCB giving an output to the fan when it should'nt.Regards Chris.
I have checked and adjusted fan speeds according to the boiler spec.
Almost certainly it is the board. If it were the fan or any other there would be a fault code.
I have been doing plumbing work for 20 years. Both servicing and new construction installation on high end homes.
Unfortunately on this occasion you were wrong it was the fan that was at fault it was not sending the correct tachometer reading back to the pcb, I did change the pcb but sent it back when same fault existed. Thank you for your help.