E3/E4/L8 - The unit is protecting because stop valves are closed or airflow is blocked.
Daikin groups E3, E4, and L8 together in the FNA-A/FNA-A9 guide as installation or airflow faults linked to closed stop valves or blocked air inlet or outlet paths.
Grounded in the official Daikin FNA25~60A2VEB(9) installer reference guide error tables for commissioning and troubleshooting.
Severity
High
Display
Shown on the user interface during test run when the outdoor unit installation is not correct.
Support first?
Often not
Models in range
FNA25A2VEB, FNA35A2VEB, FNA50A2VEB
What to do first
Start with these checks
- 1Turn the system off and do not keep retrying operation.
- 2Clear any obvious debris blocking the air inlet or outlet.
- 3If the system was recently installed or serviced, have the installer confirm stop-valve position.
Likely causes
What usually sits behind this code
Stop valves are closed
Outdoor or indoor air inlet is blocked
Outdoor or indoor air outlet is blocked
Contact support
Contact customer support if any of these apply
- !The code returns after airflow obstructions are removed.
- !No obvious blockage is present.
- !The system was commissioned recently and may have a setup error.
- - Daikin lists the same core causes for E3, E4, and L8 in this guide.
- - These are installation and protection faults rather than routine filter reminders.
Related codes
Nearby codes in this family
Source notes
Source and scope
Source: Daikin Installer Reference Guide
Official FNA-A/FNA-A9 guidance links E3, E4, and L8 to closed stop valves or blocked air paths.
Last reviewed: 2026-04-19
Daikin fault handling varies by indoor and outdoor unit combination, refrigerant type, and controller. Confirm the exact model pair and full fault history with an authorised Daikin technician before replacing parts.