Heat pumps · Error codes · Gree
U7Gree
U7 on a Gree heat pump: 4-way valve error
Short answer
On a Gree heat pump, U7 means: 4-way valve error. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 3 sources
What it means
The manual says: 4-way valve error.
Part involved: compressor, pressure switches, expansion valve, refrigerant charge.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
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 outdoor unit is not blocked by leaves, debris, snow or ice and that nothing is stored against the grilles.
What the engineer will check
- Follow the Gree troubleshooting flowchart for this code in the service manual.
- Check refrigerant pressures and charge (F-gas / flammable refrigerant competent person only).
- Check expansion valve, pressure switches/sensors and discharge temperature.
- Check outdoor coil airflow and blockages.
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
- Service Manual for VERSATI R32 SPLIT (VERSATI III Split Type Air To Water Heat Pump) ↗ · page p.109 (printed; PDF p.113) · Reviewed 23 September 2026
- VERSATI IV Split Type Air To Water Heat Pump Service Manual ↗ · page p.67 (printed; PDF p.77) · Reviewed 23 September 2026
- VERSATI V Monobloc Type Air-to-water Heat Pump Service Manual (R290) ↗ · page p.31 (printed; PDF p.34) · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026