Heat pumps · Error codes · Midea
L4Midea
L4 on a Midea heat pump: MCE error
Short answer
On a Midea heat pump, L4 means: MCE error. The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 2 sources
What it means
The manual says: MCE error.
Likely causes:
- Inverter module / compressor drive fault - follow inverter module troubleshooting (power supply, compressor windings U-V-W, inverter board, wiring).
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
What you can check
- Read and note the exact code shown on the controller display.
- Check the heat pump's breaker/isolator at the consumer unit is on.
- Restart once via the controller (OFF then ON) as the manual allows; if the code returns, call an engineer.
What the engineer will check
- Inverter module / compressor drive fault - follow inverter module troubleshooting (power supply, compressor windings U-V-W, inverter board, wiring).
Sources
- Midea M thermal Arctic Mono (4~16kW) Service Manual ↗ · not stated (MBT Confidential) · page 65 (table); inverter module troubleshooting section · Reviewed 23 September 2026
- M-Thermal A Series Split R32 Service Manual (Midea CAC, 202004) ↗ · 202004 (file v31) · page 51 (table); inverter module troubleshooting section · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026