BoilerFaultCodesDaikin E1-65 Fault Code
Also written as E165 — same fault.
The Daikin E1-65 fault code means: your boiler's internal electronic self-monitoring system has detected a technical fault and has shut down as a safety precaution.. It appears on 1 Daikin model in our database.
Technical description: Internal SCOT system error. Perform reset if needed
What causes the Daikin E1-65 fault?
This fault occurs when the boiler's internal computer system fails to communicate correctly with the safety controls that monitor the gas flame. It is usually triggered by a communication error on the circuit board or a failure in the electronic calibration system that ensures the boiler is burning gas safely. Because the boiler cannot verify that the combustion process is stable, it will shut down to prevent incorrect gas mixtures.
DIY fix possible
Locate the Power/Reset button on the front control panelPress and hold the Reset button for 2 secondsWait for the boiler to complete its restart sequence to see if the central heating resumes
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Gas Safe Register →Daikin models that show the E1-65 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Daikin E1-65 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