Daikin 4 Fault Code
The Daikin 4 fault code means: your boiler is trying to start up, but it cannot detect a flame because gas is not getting through properly or the ignition isn't sparking.. It appears on 3 Daikin models in our database.
Technical description: No flame signal - Main gas valve not opened. Gas supply pressure too low, or disappears. Condense output blocked. Check ignition unit and ignition cable. No or incorrect ignition distance, check this using the checking mold. Gas block or ignition unit is not receiving electrical current. Check earthing.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Daikin models that show the 4 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Daikin 4 fault code information on this page is sourced and cross-checked against the official Daikin service / installation manuals for each affected model.
- Daikin Altherma Hybrid EHYKOMB33 manual (PDF)
- Daikin EKOMB 22 Combi manual (PDF)
- Daikin EKOMBG 22 manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026