555.4 on a Haier heat pump: Oil temp. fails to meet the condition of system start
Short answer
On a Haier heat pump, 555.4 means: Oil temp. fails to meet the condition of system start. The heat pump keeps running with some functions stopped. 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 Super Aqua Monobloc (R32, AU..FYCRA(HW))
The manual says: Oil temp. fails to meet the condition of system start.
Part involved: ambient/oil temperature, mode setting.
On the Super Aqua Split (R32, AW..SSCHA/SNCHA + HU..WAMNA)
The manual says: oil temp. fails to meet the condition of system start.
Part involved: ambient/oil temperature.
Is it safe?
| Does the heat pump stop? | Partly |
|---|---|
| Severity | Information only |
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
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 controller mode/temperature/timer settings have not been changed; setup (DIP switch) errors need the installer.
What the engineer will check
On the Super Aqua Monobloc (R32, AU..FYCRA(HW))
- Check the standby reason parameters, the mode setting and the oil heater.
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.
On the Super Aqua Split (R32, AW..SSCHA/SNCHA + HU..WAMNA)
- Check the standby reason parameters.
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
- ATW Service Manual (Super Aqua monobloc) SYJS-03-2019 REV.A ↗ · SYJS-03-2019 REV.A · page p.73 (printed; PDF p.75) · Reviewed 23 September 2026
- Haier HU062WAMNA Service Manual (Super Aqua split R32) ↗ · page p.123 (printed) · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026