While you wait for answers, we may have found some information which could help you.
Click here for Boiler Heating Combi
saunier Duval is over pressurising when the heating is on. ?
Saunier Duval Thema F23 anyone have a link for manual?
'f19' error report - Saunier Duval 'Thermoclassic' boiler?
isotwin condens f 35 e service menu codes?
Saunier Duval timeclock not working?
Saunier Duval F35E auto-vents down to code 21 in minutes?