the boiler shows code s. 8 which in the manual means pump over run. what is that and how can i fix it please?
before this it was code f. 22 dry fire i checked expansion vessel corrected the pressure that sorted that but now it shows code s. 8.

imran beg, June 2010

s 8 on my model tells me boiler is in anti cycling mode, (saving energy cost ) check the display window and see if you see a flashing radiator symbol FLASHING this NORMAL on timed setting CH settings.
mine does approx 20 mins ON approx 9 mins OFF(anti cycling mode boiler then refires up this continues on /off till the turn off time on the clock
down load yourself a manual from valiant

wirecutterman, June 2010