Heat pumps · Error codes · Haier
E51-0Haier · Super Aqua R290 Hydro Split / Hydro All-in-One (AW..HUGHA/HVGHA)
E51-0 on a Haier Super Aqua R290 Hydro Split / Hydro All-in-One: LEVa Overcurrent Protection
Short answer
On a Haier heat pump, E51-0 means: LEVa Overcurrent Protection. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: LEVa Overcurrent Protection.
Part involved: compressor, pressure switch/sensor, expansion valve, refrigerant charge.
When it shows: LEV driver chip detection.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
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 outdoor unit is not blocked by leaves, debris, snow or ice and that nothing is stored against the grilles.
What the engineer will check
- Follow the manufacturer's troubleshooting flowchart for this code.
- Check supply voltage and phase balance.
- Check compressor windings and inverter/driver PCB per flowchart.
- Check heat-sink cooling and connections.
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.46 (printed; PDF p.4) · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026