16 on a Haier heat pump: Heat exchange unit HU in/out water temp. too high
Short answer
On a Haier heat pump, 16 means: Heat exchange unit HU in/out water temp. too high. The manual does not say whether the heat pump stops. 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: Heat exchange unit HU in/out water temp. too high.
Part involved: water flow switch/pump, water temperature.
On the Super Aqua Split (R32, AW..SSCHA/SNCHA + HU..WAMNA)
The manual says: HU in/out water temp. too high.
Part involved: water flow switch/pump, water temperature.
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 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
- 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
- Operation & Installation Manual - Air-to-Water Heat Pump Indoor Unit HU062WAMNA / HU102WAMNA (No. 0150554179) ↗ · 0150554179 · page p.17 (printed; PDF p.19) · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026