BoilerFaultCodesHeatline Boiler Fault Codes
823 fault codes across 16 Heatline boiler models — explained in plain English.
UK boiler brand owned by Vaillant Group. Entry-level to mid-range market.
Just want the most common Heatline problems?
The top 8 faults across the whole Heatline range — causes, DIY checks, repair costs.
High-severity Heatline fault codes
F0 F1 F2 F3 F5
Your boiler has stopped working because the water pressure inside the heating system has dropped too low to operate safely.
Capriz 24
Your boiler is failing to light the burner, meaning it cannot provide you with heating or hot water until the issue is repaired.
Capriz 24
Your boiler has shut itself off because it has detected that it is running too hot and could potentially damage itself.
Capriz 24
Your boiler has lost the ability to accurately measure the temperature of your hot water, which means it will stop heating the water until the faulty sensor is replaced.
Capriz 24
Your boiler has stopped working because it cannot correctly detect the temperature of the water used for your radiators.
Capriz 24
All models
16 Heatline boiler models
Capriz 24
Combi Discontinued
Capriz 28
Combi Discontinued
Capriz Plus
Combi Discontinued
Centurion 25
Combi Discontinued
Vizo 24
Combi Discontinued
Vizo 28
Combi Discontinued
Sargon 28
Combi Discontinued
Compact 24
Combi Discontinued
Compact 30
Combi Discontinued
Solaris
Combi Discontinued
Monza
Combi Discontinued
Capriz 25 System
System Discontinued
Sargon 24
Combi Discontinued
Vizo Plus
Combi Discontinued
Capriz 2
Combi Discontinued
Capriz 25/28
Combi Discontinued