BoilerFaultCodes
Heatline Boiler Fault Codes
1,032 fault codes across 22 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
F1 F2 Low water pressure Overheat Lock-out
Your boiler is trying to start up but cannot light the gas flame needed to produce heat.
Capriz 28
Your boiler has lost the ability to accurately measure the water temperature, so it has safely shut down to prevent overheating.
Capriz 28
Your boiler has switched itself off because the water level inside the heating system has dropped too low to operate safely.
Capriz 28
Your boiler has detected that it is getting dangerously hot and has automatically shut itself down to prevent damage.
Capriz 28
Your boiler has stopped working as a safety precaution because it either failed to light or became too hot.
Capriz 28
All models
22 Heatline boiler models
Capriz 28
Combi Discontinued
Capriz Plus
Combi Discontinued
Vizo 24
Combi Discontinued
Vizo 28
Combi Discontinued
Sargon 30
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
Capriz 25/28
Combi Discontinued
C24
Combi Discontinued
Compact 20
System Discontinued
S24 / S30
Combi Discontinued
Capriz 25S 28S
System Discontinued
Sargon
Combi Discontinued
Vizo Plus 24
Combi Discontinued
CaprizPlus 24a
Combi Discontinued
CaprizPlus 28
Combi Discontinued
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