While you wait for answers, we may have found some information which could help you.
Click here for Saunier Duval Combi Hot WaterSaunier Duval timeclock not working?
Saunier Duval F35E auto-vents down to code 21 in minutes?
Saunier Duval Thema F23 anyone have a link for manual?
I have a Saunier Duval Isotwin condens F 35 E with hot water No heating?
saunier duval boiler problem?
'f19' error report - Saunier Duval 'Thermoclassic' boiler?