Mitsubishi Electric Mini-Split Code E0
Soft lockout
Remote controller transmission error. The wired remote controller could not receive any transmission from the indoor unit for 3 minutes (or a sub controller received nothing for 2 minutes).
Manual wording: “Remote controller transmission error(E0)/signal receiving error(E4) - Abnormal if main or sub remote controller cannot receive any transmission normally from indoor unit of refrigerant address 0 for 3 minutes.”
Documented for: A-Control systems with a wired remote controller
Likely causes, most common first
- Contact failure at the transmission wire of the remote controller
- All remote controllers are set as 'sub' - in that case E0 shows on the remote and E4 shows on the outdoor board LEDs
- Miswiring of the remote controller
- Defective transmitting/receiving circuit of the remote controller or indoor controller board
- Noise on the remote controller transmission wire
What you can safely check yourself
- Turn the system off at the breaker, wait one minute, and turn it back on once
When to call a technician
Remote controller wiring, main/sub addressing and board swaps are technician tasks.
A Mitsubishi Electric mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Sources
- Indoor Unit Service Manual No. OCH761 Revised Edition-A - PKA-A LA Series (May 2021) (Mitsubishi Electric, PKA-A12LA, PKA-A18LA, PKA-A12LA.TH, PKA-A18LA.TH wall-mounted indoor units) · checked 2026-08-25
- Service Manual No. OCH750 Revised Edition-E - PUZ-HA Outdoor Units (May 2024) (Mitsubishi Electric, PUZ-HA24NHA1, PUZ-HA30NKA, PUZ-HA36NKA, PUZ-HA42NKA1 heat-pump outdoor units) · checked 2026-08-25