E68 on a Haier Super Aqua R290 Hydro Split / Hydro All-in-One: Communication Error with DHW I/O PCB
Short answer
On a Haier heat pump, E68 means: Communication Error with DHW I/O PCB. 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: Communication Error with DHW I/O PCB.
Part involved: PCB / communication wiring / settings.
When it shows: If the signal of the subcooled module board is not received for 2 consecutive minutes or the received data is incorrect, it will be automatically restored after receiving it correctly.
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
Resetting itself: yes.
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
- R290 Super Aqua Hydro Split & Hydro All in One Service Manual - Service Diagnosis (SYJS-03-2024 REV.A) ↗ · SYJS-03-2024 REV.A · page p.47 (printed; PDF p.5) · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026