ErrorCodeDoctor
Daikin Air Conditioner E4 error code
The E4 error means your Daikin air conditioner's low pressure switch (LPS) was activated — the refrigerant pressure dropped abnormally low. This is most commonly caused by a refrigerant leak or shortage. This requires a qualified technician — refrigerant handling requires certification and specialised equipment.
Common causes
- Refrigerant has leaked and the system is low on refrigerant
- Low pressure sensor is defective
- Outdoor unit PCB has a fault
How to fix it
-
1
Contact a qualified technician to inspect the system for refrigerant leaks and recharge if necessary
Related Daikin Air Conditioner error codes
A0
An external protection device connected to the indoor unit has been activated
A1
A fault was detected in the indoor unit PCB (control board)
A3
The drain level control system has detected an abnormality — drain may be clogged
A5
Freeze-up protection (cooling) or high pressure control (heating) has activated — check the air filter
E4 error — frequently asked questions
What does the E4 error mean on a Daikin air conditioner?
The low pressure switch was activated — possible refrigerant shortage
What causes the E4 error?
The E4 error is usually caused by: Refrigerant has leaked and the system is low on refrigerant; Low pressure sensor is defective; Outdoor unit PCB has a fault.
Can I fix the E4 error myself?
This is rated a hard fix — it often requires tools, parts, or experience, and may be safer left to a professional technician.
How much does it cost to fix the E4 error?
Fixing the E4 error on a Daikin air conditioner typically costs $150–$500, depending on parts and whether you do it yourself or hire a technician.
Is it safe to keep using my air conditioner with the E4 error?
We'd recommend addressing the E4 error before continuing to use the air conditioner, since hard-rated issues often involve a real fault rather than a minor glitch.