Gree Mini Split Error Code E4: High Discharge Temperature Protection (Meaning, Causes, Fixes)
What the code means
Gree's service manuals call E4 "High discharge temperature protection of compressor" (27 SEER Jasmine and Multi21+), "Compressor exhaust high temperature protection" (Free Match) or "Discharge protection" (Kinghome Free Match). A temperature sensor on the compressor's discharge pipe watches how hot the gas leaving the compressor is. On the Jasmine series the unit stops raising the compressor speed at 98 °C (208 °F), slows the compressor at 103 °C (217 °F) and stops it at 110 °C (230 °F); it restarts once the reading falls to 90 °C (194 °F) or below and the compressor has been off at least 3 minutes. When E4 trips in cooling or drying, the compressor and outdoor fan stop while the indoor fan keeps running; in heating, everything stops. On Multi21+ and Kinghome Free Match units, if the protection happens 6 times in a row the compressor stays off until the power is switched off and back on (the count clears after the compressor runs longer than 7 minutes). Units with indicator lamps instead of a display blink 4 times on Free Match models. Gree troubleshoots E4 with the same chart as H3 (compressor overload), since both mean the compressor is running too hot.
Likely causes
- Low refrigerant from a leak. With too little refrigerant the compressor runs hot, and Gree's E4 charts end with finding the leak and charging to the specified amount.
- An electronic expansion valve (EEV) that is unplugged, stuck or has a failed coil, which starves the system of refrigerant flow. Gree checks the valve's plug (terminal FA on the Jasmine board) and coil early in the chart.
- Poor heat exchange at the outdoor unit: a dirty coil, or a unit boxed in or recirculating its own hot air. Gree's chart says to clean the heat exchanger and improve the unit's surroundings.
- Too much load for too long, such as running hard in very hot weather or, on multi-zone systems, indoor units whose combined size is beyond the outdoor unit's capacity.
- A faulty discharge temperature sensor that reads high (Gree's sensors are 50 kΩ types), or on some models an outdoor main board that doesn't slow the compressor as it should.
Safe DIY checks
The outdoor unit has line voltage and an inverter board that can hold a dangerous charge after power is removed, and the compressor discharge pipe can be well over 100 °C (212 °F) right after an E4 trip. Leave the covers on and let a licensed technician handle the electrical tests and any refrigerant work.
- Turn the system off at the breaker or disconnect and leave it off for about 30 minutes so the compressor can cool (the Jasmine chart starts with a 30-minute wait), then turn it back on. On units that lock out after 6 trips, this power cycle is also what lets the compressor run again.
- Look at the outdoor unit. Clear leaves, grass, snow or anything stacked against it, and make sure it has open space around it so it isn't breathing its own hot exhaust.
- With the power off, rinse the outdoor coil gently from the inside out with a garden hose or a no-rinse coil cleaner. Don't use a pressure washer, which bends the fins.
- Clean or replace the indoor filters so the system isn't working harder than it needs to.
- If E4 keeps coming back, especially along with weak cooling or heating, call a technician. Gree's chart points next to the expansion valve, the refrigerant charge and the boards, which need gauges and meters.
🛠 When to call a pro
- Check the overload protector (SAT) connection and the compressor overload terminal on the main board. On the Jasmine chart the protector should read under 1000 ohms at ambient temperature; replace it if not.
- Confirm the EEV harness (terminal FA) is plugged in correctly and the valve and EKV coil work; replace the coil or valve if faulty.
- Check the refrigerant charge and leak-test the system. Repair any leak and charge to the nameplate amount per the service manual.
- On Kinghome Free Match units, measure the actual discharge temperature: if it has not reached 125 °C, test the 50 kΩ discharge sensor against its resistance table and replace it if it's off, otherwise replace the outdoor main board. If the temperature is over 110 °C and the compressor doesn't reduce its capacity, the outdoor board is suspect.
- On multi-zone systems, confirm the connected indoor capacity is within the outdoor unit's range and check the indoor/outdoor dial (DIP) settings, per the Kinghome chart.
- Only after the overload, valve, refrigerant, airflow and load checks pass should the outdoor main board (AP1) be replaced, which is the last step in Gree's chart.
Parts that commonly fix it
Always match the part number to your exact model.
Discharge temperature sensor
Gree uses a 50 kΩ discharge sensor; replace only after it tests out of range, and match the outdoor model number.
Search eBay →Refrigerant leak detector
For a technician to find the leak behind a low charge before recharging.
Search eBay →Sources
- Gree America 27 SEER Jasmine mini split service manual (E4 high discharge temperature protection of compressor, unit status, 98/103/110/90 °C thresholds, overload and high discharge temperature detection points and H3/E4 flowchart)
- Gree Kinghome Free Match 48K/56K service manual (E4 discharge protection, 6-time lockout cleared after 7 minutes, discharge temperature flowchart: 125 °C, 50 kΩ sensor, EEV, 110 °C capacity reduction, indoor capacity, leak)
- Gree Multi21+ 18K/24K service manual (E4 high discharge temperature protection of compressor, discharge protection function and 6-time lockout)
- Gree Free Match service manual (E4 compressor exhaust high temperature protection, indicator blinks 4 times)
Last reviewed 2026-10-24. Always confirm against the manual for your exact model number.