E0 on a Midea heat pump: Water flow failure (10 times of E8)
Short answer
On a Midea heat pump, E0 means: Water flow failure (10 times of E8). 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 · 4 sources
What it means
On the M-Thermal Arctic HT R290 monobloc (MHC ...WD2N7)
The manual says: Water flow failure (10 times of E8).
Likely causes:
- See R290 service manual troubleshooting (section 6) for this code.
On the M-Thermal Mono R32 (MHC ...W/D2N8-B / -B2 'Arctic')
The manual says: Water flow failure (E8 displayed 3 times).
Likely causes:
- The wire circuit is short connected or open.
- Water flow rate is too low.
- Water flow switch damaged.
- Water circuit is abnormal or not emptied.
On the M-Thermal Mono R32 compact (MHC ...WD2N8-C, 5/7/9/12/14/16 kW)
The manual says: Flow switch error (E8 displayed 3 times).
Likely causes:
- Wire circuit short or open.
- water flow rate too low.
- water flow switch failed (stuck open/closed).
On the M-Thermal Split R32 (MHA outdoor + HB hydronic box)
The manual says: Water flow failure (E8 appears 3 times).
Likely causes:
- The wire circuit is short connected or open.
- Water flow rate is too low.
- Water flow switch damaged.
Is it safe?
On the M-Thermal Arctic HT R290 monobloc (MHC ...WD2N7)
| Does the heat pump stop? | Not stated |
|---|---|
| Severity | Safety lockout |
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
On the M-Thermal Mono R32 (MHC ...W/D2N8-B / -B2 'Arctic')
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Safety lockout |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
On the M-Thermal Mono R32 compact (MHC ...WD2N8-C, 5/7/9/12/14/16 kW)
| Does the heat pump stop? | Not stated |
|---|---|
| Severity | Safety lockout |
| 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 |
|---|---|
| Severity | Safety lockout |
| 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.
- Read the system pressure gauge and report the reading to your engineer (manuals ask for more than 1 bar when cold).
- Check the filling loop valves are closed.
- 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 Mono R32 (MHC ...W/D2N8-B / -B2 'Arctic')
- The wire circuit is short connected or open.
- Water flow rate is too low.
- Water flow switch damaged.
- Water circuit is abnormal or not emptied.
On the M-Thermal Mono R32 compact (MHC ...WD2N8-C, 5/7/9/12/14/16 kW)
- Wire circuit short or open.
- water flow rate too low.
- water flow switch failed (stuck open/closed).
On the M-Thermal Split R32 (MHA outdoor + HB hydronic box)
- The wire circuit is short connected or open.
- Water flow rate is too low.
- Water flow switch damaged.
Sources
- R290 M thermal Arctic HT Series Service Manual ↗ · 2025-10-15 v5 (from file name) · page 91 · Reviewed 23 September 2026
- Midea M thermal Arctic Mono (4~16kW) Service Manual ↗ · not stated (MBT Confidential) · page 64 (table); 67 (troubleshooting) · 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 74 (printed 71) · Reviewed 23 September 2026
- M-Thermal A Series Split R32 Service Manual (Midea CAC, 202004) ↗ · 202004 (file v31) · page 50 (table); 53 (troubleshooting) · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026