Heat pumps · Error codes · Midea
C3Midea · M-Thermal Arctic HT R290 monobloc (MHC ...WD2N7)
C3 on a Midea M-Thermal Arctic HT R290 monobloc: Current transformer failure or circuit failure of IBH PCB (units with IBH)
Short answer
On a Midea heat pump, C3 means: Current transformer failure or circuit failure of IBH PCB (units with IBH). The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Current transformer failure or circuit failure of IBH PCB (units with IBH).
Likely causes:
- See R290 service manual troubleshooting (section 6) 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
- See R290 service manual troubleshooting (section 6) for this code.
Sources
- R290 M thermal Arctic HT Series Service Manual ↗ · 2025-10-15 v5 (from file name) · page 93 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026