We may have found other answers which could help you.
Click here for Saunier Duval Boiler CondensSaunier Duval timeclock not working?
saunier Duval is over pressurising when the heating is on. ?
Saunier Duval F35E auto-vents down to code 21 in minutes?
Saunier Duval Isofast condens F35E....nothing working?
saunier duval boiler problem?
Saunier D’uval therma classuc?