High Pressure Protection

What it means

This code appears on Gree split air conditioners when the system detects excessive refrigerant pressure on the high-pressure side, either through a high-pressure switch or through outdoor temperature readings, depending on the model. The unit stops the compressor to protect it and retries after a few minutes; if protection repeats, it may lock out until power is reset. The same code can mean something else on other brands.

Models covered: Gree split (wall-mounted) air conditioners, mainly inverter models; the code shows on the indoor unit display. Older non-inverter models may show fewer codes.

Related codes: E3E4E5H3F4

Symptoms4

• Cooling stops shortly after start, returns, then stops again.
• The outdoor unit is very hot and its fan is weak or not running.
• The code tends to appear in the hot afternoon hours rather than at night.
• Air from the indoor unit is not cold enough.

Possible causes6

• Dust and sand clogging the condenser coil, which is the most common cause in dusty climates.
• Outdoor fan motor or fan capacitor failure, or a slow-running fan.
• Poor airflow around the outdoor unit: too close to a wall, hot air from other units, or intense direct sun.
• Refrigerant overcharge after an inaccurate top-up, or air and moisture in the circuit after installation.
• Partial blockage of the capillary tube, electronic expansion valve or strainer.
• Faulty high-pressure switch or its wiring, condenser temperature sensor, or control board.

How to diagnose5

1. Switch the unit off at the breaker for a few minutes, restart it and note when the code returns.
2. Inspect the outdoor unit: are the fins blocked with dust, does the fan spin at normal speed, is there enough free space around it?
3. The technician measures operating pressure with gauges and compares it with the manufacturer chart for the refrigerant type and outdoor temperature.
4. The technician checks the outdoor fan motor, its capacitor and connections.
5. The technician checks the high-pressure switch (where fitted) and the condenser sensor against the manufacturer table.

How to fix5

1. Wash the condenser and the whole outdoor unit and clear anything blocking airflow.
2. Replace the fan capacitor or the outdoor fan motor if it is weak.
3. Relocate or shade the outdoor unit without restricting its airflow.
4. Have a licensed technician recover, evacuate and recharge the refrigerant by weight if it is overcharged or contaminated with air.
5. Replace the pressure switch, sensor or board based on the tests, then run the unit, watch the pressures and confirm the code does not return.

A condenser wash or a new fan capacitor is often enough and cheap; the cost rises if the circuit needs evacuation and recharge or the outdoor control board has failed.

Prices are rough estimates including the part and the technician’s fee, and vary with brand, model and part source.
Prices last updated: September 2026

Frequently asked questions