BoilerFaultCodesDaikin 12-64 Fault Code
Also written as 1264 — same fault.
The Daikin 12-64 fault code means: your boiler is having trouble managing the flame correctly and has locked itself for safety after failing to stabilise.. It appears on 1 Daikin model in our database.
Technical description: Ion control deviation is too big – try resetting the boiler
What causes the Daikin 12-64 fault?
This fault happens when the boiler's internal sensor detects that the flame is burning inconsistently or not matching the expected safety signals. It is often caused by a worn-out sensing probe that can no longer 'see' the flame clearly, or a gas valve that is failing to deliver the correct amount of fuel to keep the burner stable.
DIY fix possible
Locate the reset button on your boiler's control panelPress and hold the reset button for at least 5 secondsWait for the boiler to attempt to restart; if the code returns immediately, call a Gas Safe engineer
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Gas Safe Register →Daikin models that show the 12-64 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Daikin 12-64 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