F8 on a Gree heat pump: Heat exchanger-entering water temperature sensor error
Short answer
On a Gree heat pump, F8 means: Heat exchanger-entering water temperature sensor error. 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 Versati II (R410A)
The manual says: Heat exchanger-entering water temperature sensor error.
Part involved: temperature/pressure sensor.
Likely causes:
- The plug on temperature sensor is not correctly connected to the socket on mainboard.
- The resistance of temperature sensor is not correct.
On the Versati III Monobloc (R32)
The manual says: Enthalpy-enhancing sensor error.
Part involved: temperature/pressure sensor.
Is it safe?
On the Versati II (R410A)
| Does the heat pump stop? | Partly |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
Resetting itself: yes.
On the Versati III Monobloc (R32)
| Does the heat pump stop? | Partly |
|---|---|
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
Resetting itself: unknown.
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 controller display is lit; a single power cycle at the isolator may be tried only if your installer or manual allows it.
What the engineer will check
- Follow the Gree troubleshooting flowchart for this code in the service manual.
- Check sensor connector and wiring.
- Measure sensor resistance against the manual's sensor table.
- Replace sensor or PCB as indicated by the troubleshooting flowchart.
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
- Air to Water Heat Pump Service Manual Versati II (T1/R410A/50Hz, GC201308-) ↗ · GC201308 · page p.61 (printed; PDF p.64) · Reviewed 23 September 2026
- VERSATI III Air To Water Heat Pump (Monobloc) Service Manual ↗ · page p.121 (printed; PDF p.121) · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026