Heat pumps · Error codes · Gree
H3Gree
H3 on a Gree heat pump: Compressor internal overload protection
Short answer
On a Gree heat pump, H3 means: Compressor internal overload protection. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 2 sources
What it means
The manual says: Compressor internal overload protection.
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 supply voltage and phase balance.
- Check compressor windings and inverter/driver PCB per flowchart.
- Check heat-sink cooling and connections.
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.63 (printed; PDF p.66) - '2) Drive Failure Code' · 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