555.5 on a Haier Super Aqua Monobloc): Outdoor unit mode does not match indoor unit mode (outdoor unit set to cooling-only or heating-only, conflicting with indoor unit mode) - standby
Short answer
On a Haier heat pump, 555.5 means: Outdoor unit mode does not match indoor unit mode (outdoor unit set to cooling-only or heating-only, conflicting with indoor unit mode) - standby. The heat pump keeps running with some functions stopped. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Outdoor unit mode does not match indoor unit mode (outdoor unit set to cooling-only or heating-only, conflicting with indoor unit mode) - standby.
Part involved: ambient/oil temperature, mode setting.
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
- 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.
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
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026