Et Low

Daikin Et Fault Code

Also written as ET — same fault.

The Daikin Et fault code means: your boiler is currently set to provide hot water but not central heating, often because the summer operation mode has been activated.. It appears on 1 Daikin model in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Summer mode to be activated by button
Typical repair cost £0 (including labour)

DIY fix possible

Locate the button with the sun/snowflake icon or the 'Mode' button on the control panel.Press the button to toggle away from 'Summer' mode until the radiator icon appears.Check if the display returns to showing the temperature or pressure.

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Daikin models that show the Et fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Daikin Et 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 7 July 2026