Daikin Mini-Split Code E3
Soft lockout
Actuation of high pressure switch. The high-pressure safety switch opened because refrigerant discharge pressure climbed past its setpoint (about 4.15 MPa on Atmosphera, 4.0 MPa on RMXS).
Manual wording: “E3 Actuation of high pressure switch”
Documented for: FTXM-W/V (Atmosphera), RMXS multi-split outdoor units
Likely causes, most common first
- Actuation of the high pressure switch (S1PH)
- Closed stop valve
- Disconnection of connector S40 or of the two terminals at the high pressure switch
- Broken S1PH harness
- Defective high pressure switch
- Defective outdoor unit PCB
- Defective high pressure sensor (multi-split)
- Instantaneous power failure (multi-split)
What you can safely check yourself
- Check the outdoor unit is not blocked by leaves, snow, plants or a fence and has open space around it
- Check the outdoor coil is not visibly plugged with dirt or cottonwood
- Turn the system off at the breaker or disconnect switch and back on once after clearing anything blocking airflow
When to call a technician
Stop valve position, pressure switch testing and refrigerant charge are all technician work. Never bypass or jumper the high-pressure switch.
A Daikin mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Sources
- Service Manual - Inverter Pair Wall Mounted Type FTXM-W/V Series (SiUS042113EA) (Daikin, FTXM-W / FTXM-V (Daikin Atmosphera) wall-mount heat pump) · checked 2026-08-25
- Service Manual - Multi-Split Type Air Conditioners RMXS-L Series (SiUS181631EA) (Daikin, RMXS48LVJU outdoor, BPMKS048A2U/049A3U branch provider, CTXG/CTXS/FTXS/CDXS/FDXS/FVXS/FFQ indoor units) · checked 2026-08-25