Heat pumps · Error codes · Haier
E7Haier · HPM-Nd2 monobloc (R290, Haier Water Heater Co.)
E7 on a Haier HPM-Nd2 monobloc: Wire controller communication failure
Short answer
On a Haier heat pump, E7 means: Wire controller communication failure. 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: Wire controller communication failure.
Part involved: PCB / communication wiring / settings.
Likely causes:
- Communication circuit terminal is loose, broken or miswired.
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
Resetting itself: unknown.
What you can check
- Note the code shown on the controller and the unit model numbers (on the rating plate label) before contacting your installer.
- Check the heat pump's breaker/isolator at the consumer unit is on; do not open any casing.
- Check the controller display is lit; a single power cycle at the isolator may be tried only if your installer or manual allows it.
- Check controller mode/temperature/timer settings have not been changed; setup (DIP switch) errors need the installer.
What the engineer will check
- Follow the manufacturer's troubleshooting flowchart for this code.
- Check communication wiring, terminals and fuses between units/controller.
- Check DIP/rotary switch and address settings.
- Replace PCB if the fault persists per the flowchart.
Who to ask for: Heat pump engineer.
Certification: Heat pump installer competence; F-gas / flammable-refrigerant (R290/R32) handling competence for any refrigerant-circuit work.
What you might notice
Sources
- Installation and service instructions - HPM08/10/12/14/16-Nd2 (Haier R290 monobloc) ↗ · page p.85 (printed; ManualsLib viewer p.91) · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026