Heat pumps · Error codes · Midea
LCBMidea · M-Thermal Arctic HT R290 monobloc (MHC ...WD2N7)
LCB on a Midea M-Thermal Arctic HT R290 monobloc: Overvoltage of PFC bus or PFC half bus (3-phase units)
Short answer
On a Midea heat pump, LCB means: Overvoltage of PFC bus or PFC half bus (3-phase units). 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: Overvoltage of PFC bus or PFC half bus (3-phase units).
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