Gree Mini Split Error Code H7: Compressor Desynchronizing (Out of Step) Protection (Meaning, Causes, Fixes)
What the code means
Gree's service manuals list H7 as an outdoor unit protection: "Desynchronizing of compressor" in the 27 SEER Jasmine manual, "Compressor desynchronizing" on Multi21+ and Kinghome/Super Free Match units, and "Compressor loss step protection" on Free Match units. An inverter compressor is driven by the outdoor board, which has to keep its output in step with the motor. When the motor stalls or slips out of step, usually because it's working against too much pressure or isn't getting a clean supply, the board stops it and sets H7. According to the Jasmine malfunction table, in cooling and dry mode the compressor stops while the indoor fan keeps running, and in heating mode the whole unit stops. On Free Match units the indicator lamp blinks 7 times, and on Kinghome/Super Free Match outdoor boards the LED flashes 18 times. On Multi21+ and Free Match units the code can be viewed through the remote within 200 seconds and is displayed directly after 200 seconds.
Likely causes
- System pressure too high: dirty indoor or outdoor coils, an outdoor unit that's covered or crowded so it can't get rid of heat, or a fan that isn't running. Gree's checks start with the unit's 'radiation' (heat rejection).
- Too much refrigerant in the system, which Gree's H7 flowchart names directly.
- Supply voltage out of range. The Jasmine manual's check for this group of compressor faults expects 210 to 250 VAC between L and N on its 230 V models.
- Compressor wires (U, V, W) loose or connected in the wrong order at the outdoor board.
- A stuck or broken electronic expansion valve (EEV).
- A failed outdoor main board, or less often a failed compressor.
Safe DIY checks
The outdoor inverter board holds high DC voltage that can stay charged after the power is switched off, and the voltage checks are made with the unit live. Keep power off for cleaning and visual checks, and leave live measurements, refrigerant work, and board, valve, or compressor replacement to a qualified HVAC technician.
- Turn the unit off at the disconnect and wait at least 3 minutes before restarting. Gree's flowchart for H7 at start-up first asks whether the compressor had been stopped for longer than 3 minutes, so a quick off-and-on can trigger it again.
- Clear anything blocking the outdoor unit (leaves, snow, covers, plants, stored items) so air flows freely through the coil and out the fan.
- With the power off, rinse the outdoor coil gently with a garden hose from the inside out if it's dirty, and clean or replace the indoor unit's filters.
- Restart the unit and watch the outdoor fan. If the fan doesn't spin, or H7 keeps coming back with clean coils and clear airflow, the remaining checks (voltage, compressor wiring, EEV, refrigerant charge, board) are for an HVAC technician.
🛠 When to call a pro
- Multi21+ flowchart (H7 as soon as the unit starts): confirm the compressor had been off for more than 3 minutes, check the compressor wiring is connected properly, check whether the electronic expansion valve is broken and replace it if so, then replace the outdoor mainboard, and if the fault remains, replace the compressor.
- Multi21+ flowchart (H7 during operation): check the outdoor unit is working and its fan terminal is connected well, improve heat rejection (clean the heat exchanger, improve ventilation), confirm the input voltage is normal, and if there's too much refrigerant, charge it according to the service manual. If all are normal, replace the outdoor mainboard.
- Jasmine manual (refers H7 to the same analysis as IPM protection and phase current overcurrent): measure L to N at the outdoor terminal block with an AC voltmeter; it should be 210 to 250 VAC on these models. Check the compressor U, V, W wires against the wiring diagram.
- Jasmine manual: with power off, measure resistance between the three compressor terminals (U, V, W); the three readings should be almost the same. Then measure each terminal to the copper pipe; if it's not more than 500 ohms, replace the compressor.
- Jasmine manual: also check whether the indoor and outdoor heat exchangers are dirty or covered, whether the indoor and outdoor fans run normally, whether system pressure is too high, and whether that's from too much refrigerant. Correct each one; if the unit still won't run normally, replace the control board.
Parts that commonly fix it
Always match the part number to your exact model.
Outdoor main control board
Gree's flowcharts replace the outdoor mainboard once wiring, voltage, airflow, charge and the expansion valve check out. It must match your outdoor unit's exact model.
Search eBay →Coil cleaner
For cleaning a dirty outdoor coil, one of the first things Gree checks for H7.
Search eBay →Sources
- Gree 27 SEER Jasmine mini split service manual (malfunction table: H7 desynchronizing of compressor, compressor stops in cool/dry with indoor fan running, whole unit stops in heat; IPM protection / phase current overcurrent analysis with 210-250 VAC, UVW resistance and 500 ohm checks)
- Gree Multi21+ service manual, models MULTI18HP230V1CO / MULTI24HP230V1CO (error list: compressor desynchronizing H7; 3. Compressor desynchronizing malfunction, main checking points and flowcharts)
- Gree Free Match service manual (error list: compressor loss step protection H7, lamp blinks 7 times)
- Gree America Kinghome / Super Free Match 48K-56K service manual (outdoor error table: compressor desynchronizing, flash 18 times, H7)
Last reviewed 2026-10-24. Always confirm against the manual for your exact model number.