BoilerFaultCodesDaikin 12-65 Fault Code
Also written as 1265 — same fault.
The Daikin 12-65 fault code means: your boiler is having trouble starting the burner safely and needs a simple restart to clear a temporary electronic glitch.. It appears on 1 Daikin model in our database.
Technical description: Ignition scott actuators error – try resetting the boiler
What causes the Daikin 12-65 fault?
This fault occurs when the boiler's internal computer is unable to correctly calibrate the movement of the gas valve during the startup sequence. The most common reason is a temporary communication lag between the control board and the ignition components, though it can also indicate that the components are beginning to wear out.
DIY fix possible
Locate the Reset button on the boiler control panelPress and hold the Reset button for 5 secondsWait for the boiler to complete its startup sequence
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Gas Safe Register →Daikin models that show the 12-65 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Daikin 12-65 fault code information on this page is sourced and cross-checked against the official Daikin service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026