Heat pumps · Error codes · Midea
E7Midea
E7 on a Midea heat pump: Tbt balance tank temperature sensor / cascade final outlet water temperature sensor error
Short answer
On a Midea heat pump, E7 means: Tbt balance tank temperature sensor / cascade final outlet water temperature sensor error. 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 · 2 sources
What it means
On the M-Thermal Arctic HT R290 monobloc (MHC ...WD2N7)
The manual says: Tbt balance tank temperature sensor / cascade final outlet water temperature sensor error.
Likely causes:
- See R290 service manual troubleshooting (section 6) for this code.
On the M-Thermal Split R32 (MHA outdoor + HB hydronic box)
The manual says: Balance tank upper temperature sensor (Tbt1) error.
Likely causes:
- Temperature sensor not connected properly or has malfunctioned.
- Damaged hydronic box main PCB.
Is it safe?
On the M-Thermal Arctic HT R290 monobloc (MHC ...WD2N7)
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
On the M-Thermal Split R32 (MHA outdoor + HB hydronic box)
| Does the heat pump stop? | Yes |
|---|---|
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
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
On the M-Thermal Arctic HT R290 monobloc (MHC ...WD2N7)
- See R290 service manual troubleshooting (section 6) for this code.
On the M-Thermal Split R32 (MHA outdoor + HB hydronic box)
- Temperature sensor not connected properly or has malfunctioned.
- Damaged hydronic box main PCB.
Sources
- R290 M thermal Arctic HT Series Service Manual ↗ · 2025-10-15 v5 (from file name) · page 91 · Reviewed 23 September 2026
- M-Thermal A Series Split R32 Service Manual (Midea CAC, 202004) ↗ · 202004 (file v31) · page 50 (table); 59 (troubleshooting) · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026