P6 on a Midea heat pump: Inverter module protection (shown on user interface when any of L0, L1, L2, L4, L5, L7, L8 or L9 occur)
Short answer
On a Midea heat pump, P6 means: Inverter module protection (shown on user interface when any of L0, L1, L2, L4, L5, L7, L8 or L9 occur). The manual does not say whether the heat pump stops. An engineer is needed to fix the cause. The wording differs by model range — each is shown below.
Reviewed 23 September 2026 · 3 sources
What it means
On the M-Thermal Mono R32 (MHC ...W/D2N8-B / -B2 'Arctic')
The manual says: Inverter module protection (shown on user interface when any of L0, L1, L2, L4, L5, L7, L8 or L9 occur).
Likely causes:
- See service manual troubleshooting procedure for this code.
On the M-Thermal Mono R32 compact (MHC ...WD2N8-C, 5/7/9/12/14/16 kW)
The manual says: Module protection.
Likely causes:
- Low supply voltage.
- insufficient spacing.
- dirty coil.
- fan not running.
- refrigerant overcharge.
- low water flow/air.
- loose outlet sensor.
- undersized cylinder coil.
- loose module wires/screws or dried thermal paste.
- drive board or compressor defective.
On the M-Thermal Split R32 (MHA outdoor + HB hydronic box)
The manual says: Inverter module protection.
Likely causes:
- See service manual troubleshooting procedure for this code.
Is it safe?
Switch the heat pump off at its isolator and call an engineer.
| 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.
- If the breaker has tripped or trips again, leave the unit off and call an engineer; do not keep resetting it.
What the engineer will check
On the M-Thermal Mono R32 (MHC ...W/D2N8-B / -B2 'Arctic')
- See service manual troubleshooting procedure for this code.
On the M-Thermal Mono R32 compact (MHC ...WD2N8-C, 5/7/9/12/14/16 kW)
- Low supply voltage.
- insufficient spacing.
- dirty coil.
- fan not running.
- refrigerant overcharge.
- low water flow/air.
- loose outlet sensor.
- undersized cylinder coil.
- loose module wires/screws or dried thermal paste.
- drive board or compressor defective.
On the M-Thermal Split R32 (MHA outdoor + HB hydronic box)
- See service manual troubleshooting procedure for this code.
Sources
- Midea M thermal Arctic Mono (4~16kW) Service Manual ↗ · not stated (MBT Confidential) · page 65 · Reviewed 23 September 2026
- M-thermal Mono ATW Heat Pump Installation and Owner's Manual (5/7/9/12/14/16 kW) ↗ · 16125300001699 V4.0 · page PDF 78 (printed 75) · Reviewed 23 September 2026
- M-Thermal A Series Split R32 Service Manual (Midea CAC, 202004) ↗ · 202004 (file v31) · page 51 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026