E15 on a Haier Super Aqua R290 Hydro Split / Hydro All-in-One: Anti-freeze Abnormality
Short answer
On a Haier heat pump, E15 means: Anti-freeze Abnormality. 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: Anti-freeze Abnormality.
Part involved: water flow switch/pump, water temperature.
When it shows: In cooling mode, when the HU detects Twi or Two≤3°C or Two-Twi>=3°C& min{Twi,Two}≤10°C for 1 minute, it reports antifreeze protection; Recover after 10 minutes. If it occurs 3 times in an hour, confirm the failure.
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Severity | Safety lockout |
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
Resetting itself: yes (until locked).
Manual reset: Confirmed/locked after 3 occurrences in an hour; engineer reset after the cause is fixed.
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 heating system pressure gauge shows the pressure your installer set (typically about 1-2 bar); if it is low, report it rather than refilling unless you have been shown how. Check any filling loop is closed.
- Check radiator valves / underfloor zones are open and thermostats are calling for heat.
- In freezing weather keep the heat pump powered on (its frost protection relies on power) and check the outdoor unit is clear of snow/ice.
What the engineer will check
- Follow the manufacturer's troubleshooting flowchart for this code.
- Check water pressure, strainer/filter and air in the system.
- Check circulation pump operation and flow sensor/switch.
- Check heater safety thermostats and wiring.
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.43 (printed; PDF p.1) · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026