BoilerFaultCodes
Saunier Duval Boiler Fault Codes
329 fault codes across 18 Saunier Duval boiler models — explained in plain English.
French brand owned by Vaillant Group. Popular across Europe.
Just want the most common Saunier Duval problems?
The top 8 faults across the whole Saunier Duval range — causes, DIY checks, repair costs.
High-severity Saunier Duval fault codes
F1 F4 Red flashing light Flashing pressure F1
Your boiler is attempting to start up, but it is unable to keep the flame alight once it ignites, so it safely shuts itself down.
Themaclassic F24E
Your boiler is attempting to start its flame but is unable to stay lit, causing it to shut down for safety reasons.
Themaclassic F24E
Your boiler has detected a general issue and has entered a safety lockout mode.
Themaclassic F24E
Your boiler has detected that the water pressure level inside the heating system has dropped below the required amount to operate safely.
Themaclassic F24E
Your boiler is failing to light the internal flame needed to produce heat or hot water.
Themaclassic Plus F30E
All models
18 Saunier Duval boiler models
Themaclassic F24E
Combi Discontinued
Themaclassic Plus F30E
CombiSystem Discontinued
Thelia 23E
Combi Discontinued
Isofast F28E
Combi
Isomax F30E
Combi Discontinued
Ecosy 24E
Combi Discontinued
Opalia F24E
Water Heater Discontinued
Isotwin F30E
Combi Discontinued
SD 30e
Combi Discontinued
Isofast
Combi Discontinued
Sylva
Combi Discontinued
Xeon 120 FF
Regular Discontinued
Enviroplus
CombiSystem Discontinued
Semia Condens F30 E
Combi Discontinued
Thelia
Combi Discontinued
Thema F 30 E Plus
CombiSystem Discontinued
Xeon 30ff
Regular Discontinued
Themaclassic F35E
Combi Discontinued
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