Gree Mini Split Error Code H3: Compressor Overload Protection (Meaning, Causes, Fixes)
What the code means
Gree's error tables list H3 as "Overload protection for compressor" (27 SEER Jasmine), "Compressor over load protection" (Free Match) or "Compressor overload protection" (Multi21+ and Gree's after-sales error code list). The compressor carries an overload protector (SAT) wired back to the outdoor board; the Jasmine manual's overload sensor stops the compressor above 115 °C and releases the protection once it cools below 95 °C. When the protector trips, the compressor stops. In cooling and drying the indoor fan keeps running; in heating the whole unit stops. On Multi21+ units the compressor restarts on its own after at least 3 minutes once the overload switch resets, but if the protection happens more than 6 times the unit locks out until power is switched off and back on (the count clears after the compressor runs longer than 30 minutes). On Free Match and Multi21+ models the code can be viewed through the remote within the first 200 seconds and is shown directly after that; units with indicator lamps instead of a display blink 3 times. Gree troubleshoots H3 with the same chart it uses for high discharge temperature (E4), because both point to a compressor running too hot.
Likely causes
- A loose or disconnected overload protector wire or terminal (OVC-COMP on the Jasmine board); Gree says the resistance across this terminal should normally be under 1 ohm
- A failed overload protector (SAT) on the compressor
- A loose or failed electronic expansion valve: its FA wiring terminal or the EKV coil
- Refrigerant leak or low charge, which makes the compressor run hot
- Poor heat exchange: a dirty outdoor coil, blocked air inlet or outlet, or a bad spot for the outdoor unit to shed heat
- Too much load on the system for long periods, or a faulty discharge temperature sensor (Jasmine's main check points)
- A faulty outdoor control board, the last step on Gree's chart
Safe DIY checks
Unplug the appliance or switch off its breaker before opening panels.
- Write down the code and when it appears (right after startup, or after a long run on a hot day). That helps a technician tell a wiring fault from an overheating problem.
- Look at the outdoor unit: clear leaves, grass, snow or stored items from around it, and make sure nothing blocks the air coming out of the fan.
- If the outdoor coil is visibly dirty, turn the power off at the disconnect and gently rinse it with a garden hose from the inside out where you can reach. Don't use a pressure washer.
- Clean the indoor filters too, since an overloaded system runs the compressor harder.
- Turn the unit off at the breaker and leave it off for 20 to 30 minutes so the compressor and its protector can cool, then restore power. Gree's charts start with the power off for that long.
- If H3 keeps coming back, stop resetting it and call a licensed HVAC technician. The checks inside the outdoor unit involve live electrical parts and refrigerant.
🛠 When to call a pro
- With the unit powered off for 20 to 30 minutes, confirm the overload protector SAT is connected to the outdoor board as shown on the wiring diagram.
- At ambient temperature, measure the overload protector's resistance with an ohmmeter. Gree's chart passes it under 1000 ohms (the error list notes it is normally under 1 ohm); otherwise replace the overload protector.
- Check that the electronic expansion valve's FA wiring terminal is connected well, then check the EKV coil: the resistance between each of the first four pins near the terminal hole and the fifth pin should be about the same and under 100 ohms. Replace the coil if it isn't.
- Check for a refrigerant leak and, if needed, repair it and charge refrigerant to the nameplate specification.
- Check the discharge temperature sensor, heat exchange at both coils and whether the system is badly overloaded, per Gree's main detection points.
- If all of that checks out and H3 remains, Gree's chart ends with replacing the outdoor control board.
Parts that commonly fix it
Always match the part number to your exact model.
Compressor overload protector (exact part for your outdoor model)
Gree replaces the overload protector SAT when its resistance is out of range; match the outdoor unit's model number.
Search eBay →Electronic expansion valve coil
Gree replaces the EKV coil when its pin resistances are uneven or over 100 ohms.
Search eBay →Digital multimeter (CAT III rated)
For the overload protector and expansion valve coil resistance checks, done by a qualified technician with the power off.
Search eBay →Sources
- Gree 27 SEER Jasmine mini split service manual: H3 overload protection for compressor (malfunction table and OVC-COMP terminal under 1 ohm), overload protection above 115 °C / below 95 °C, and 5. Overload and high discharge temperature malfunction (main detection points and H3/E4 flowchart)
- Gree Multi21+ service manual, models MULTI18HP230V1CO / MULTI24HP230V1CO: 2.7 Compressor overload protection (3-minute restart, 6-time lockout, 30-minute count clear), H3 in the malfunction list and the compressor overload flowchart
- Gree Free Match service manual: error list (compressor over load protection H3, lamp blinks 3 times, viewable by remote within 200 s)
- Gree Mini After-sales Service Manual (error code manual, Gree Australia): overload protection of compressor (flashes 3 times, overload protector normally under 1 ohm) and 4.1 overload / high discharge temperature flowchart (SAT, FA terminal, EKV coil under 100 ohms, refrigerant, control board)
Last reviewed 2026-10-24. Always confirm against the manual for your exact model number.