Introduction
This manual provides essential information for the safe and efficient operation, installation, and maintenance of your Gree Multi21+ Dual-Zone Floor/Ceiling Mini Split Air Conditioner Heat Pump. Please read this manual thoroughly before installation and use, and retain it for future reference.
Safety Information
WARNING: Improper installation, adjustment, alteration, service, or maintenance can cause property damage, injury, or death. Refer to this manual. For assistance or additional information, consult a qualified installer or service agency.
- Installation must be performed by a state-licensed HVAC contractor to ensure eligibility for warranty and safe operation.
- Ensure the power supply matches the unit's requirements (208/230V).
- Do not attempt to repair or service the unit yourself. Contact qualified personnel.
- Keep children and pets away from the outdoor unit during operation.
- Ensure proper ventilation around the outdoor unit.
Product Overview
The Gree Multi21+ Dual-Zone system is an inverter-driven mini split air conditioner and heat pump designed for efficient heating and cooling of two separate zones. It utilizes eco-friendly R410A refrigerant.

Figure 1: Overview of the Gree Multi21+ Dual-Zone Mini Split system, showing two indoor floor/ceiling units, their respective remote controls, and the single outdoor condenser unit.

Figure 2: A single Gree Multi21+ Floor/Ceiling indoor unit, designed for flexible installation, accompanied by its wired wall controller and wireless remote control.

Figure 3: The Gree Multi21+ outdoor condenser unit, featuring the G10 inverter technology for energy efficiency and quiet operation.
Setup and Installation
The Gree Multi21+ system requires professional installation by a licensed HVAC contractor. This ensures correct setup, adherence to safety standards, and proper system performance, which is also a condition for warranty eligibility.
Key Installation Considerations:
- Line Set: Two sets of 1/4" x 3/8" line sets are required but not included with the unit.
- Indoor Unit Placement: The Multi21+ Universal Floor/Ceiling indoor units are versatile and can be suspended from a ceiling or mounted low on a wall. This design is particularly suitable for spaces with limited wall space, such as restaurants or hallways.
- Electrical Connection: The system operates on 208/230V. Ensure the electrical supply meets these requirements and is installed by a qualified electrician.
Operating Instructions
Your Gree Multi21+ system provides both heating and cooling functionalities, managed independently for two zones. The system is controlled via the provided wired wall controllers and wireless remote controls.
Key Features:
- G10 Inverter Technology: This advanced technology optimizes energy consumption, reduces operational noise from the outdoor unit, and maintains stable room temperatures by avoiding the frequent on/off cycles of conventional systems.
- Dual-Zone Control: Each indoor unit can be set to a different temperature and mode (heating or cooling), allowing for customized comfort in two distinct areas.
- Air Purification Filter: The indoor units are equipped with an air purification filter to improve indoor air quality.

Figure 4: Visual representation of the Gree system's dual functionality, providing both cooling (blue) and heating (orange) capabilities for year-round comfort.

Figure 5: Icons illustrating key features and certifications of the Gree Multi21+ system, including a 5-year parts warranty, R410A refrigerant, heating & cooling, ETL listing, G10 Inverter Technology, AHRI certification, and Energy Star rating (except 42k model).
Maintenance
Regular maintenance ensures optimal performance and longevity of your Gree Multi21+ system. Always disconnect power to the unit before performing any maintenance.
- Air Filter Cleaning: The air filters in the indoor units should be cleaned regularly (e.g., monthly, or more frequently depending on usage and air quality). Refer to the specific indoor unit manual for instructions on how to access and clean the filters.
- Outdoor Unit Cleaning: Keep the outdoor unit free from obstructions, leaves, dirt, and debris. Periodically clean the outdoor coil with a soft brush or water hose (low pressure) to maintain airflow.
- Professional Inspection: It is recommended to have a licensed HVAC technician perform an annual inspection and professional cleaning of the entire system.
Troubleshooting
Before contacting service, review the following common issues and solutions:
- Unit Not Turning On: Check power supply, circuit breaker, and ensure the remote control batteries are functional.
- Insufficient Cooling/Heating: Verify temperature settings, ensure air filters are clean, and check for any obstructions to airflow at indoor or outdoor units.
- Unusual Noises: Minor operational noises are normal. If loud or unusual noises occur, contact a qualified technician.
- Water Leakage: Ensure the condensate drain line is not clogged or kinked.
For persistent issues, contact a licensed HVAC professional.
Specifications
| Feature | Detail |
|---|---|
| Brand | GREE |
| Model Number | MULTI18CFLR201 |
| System Type | Dual-Zone Mini Split Air Conditioner Heat Pump |
| Cooling Capacity | 18,000 BTU (1.5 Tons) |
| Voltage | 208/230 Volts |
| SEER Rating | 22 |
| Refrigerant | R410A |
| Noise Level (Outdoor) | 56 Decibels |
| Indoor Unit Dimensions (WxHxD) | 48" x 27.6" x 8.9" (for 9k, 12k, 18k, 24k BTU units) |
| Outdoor Unit Dimensions (WxHxD) | 38" x 27.6" x 15.6" (for 18,000 BTU unit) |
| Item Weight | 300 pounds (total system) |
| Material Type | Steel |
| Special Features | Air Purification Filter, G10 Inverter Technology |

Figure 6: Detailed table showing measurements for various BTU capacities of Gree Floor/Ceiling indoor and outdoor units.

Figure 7: A table detailing system performance specifications for various models, including cooling/heating capacity, airflow, sound level, and line set sizes.
Warranty Information
The Gree Multi21+ system comes with a manufacturer's warranty:
- Parts: 5 Years
- Compressor: 7 Years
Important Note: To be eligible for warranty coverage, installation must be performed by a state-licensed HVAC contractor. Failure to comply with this requirement may void the warranty.
Support
For technical support, service inquiries, or to locate a licensed HVAC contractor, please refer to the official Gree website or contact their customer service department. Always provide your model number (MULTI18CFLR201) and serial number when seeking support.





