GREE FLEXX Ultra R32
Quick Start Guide

It covers FLEXX Ultra R32 air handlers (FXU**HP230V1R32AH, in 24, 36, 48, and 60kBtu sizes) and the FXU36HP230V1R32AO and FXU60HP230V1R32AO outdoor units.

By default, capacity is set at the larger rating (36kBtu or 60kBtu), communication is RS485, and defrost, operating mode, and noise reduction are all set to Standard. Shut off power before changing any dip switch, and make sure outdoor unit capacity matches the indoor unit.

Yes. The 36kBtu outdoor unit can be configured to 24kBtu, and the 60kBtu unit to 48kBtu, using dip switch SA3 #2 (ON = larger capacity, OFF = smaller). Efficiency ratings may change with a change in capacity rating, and outdoor capacity must always match the indoor unit.

The control type is set with dip switch SA1 #1: OFF is RS485 communication (the factory default, with H1/H2 connected) and ON is 24V control. SA1 #1 must be set the same at both the outdoor unit and the air handler, with power shut off before changing the switch.

GREE recommends always connecting H1/H2 between the indoor and outdoor unit, even under 24V control; they carry RS485 communication and are also used by the GREE controller. If H1/H2 are not connected, the SA1 #1 dip switch must be set to 24V at both the outdoor unit and the air handler. Run H1/H2 on a separate cable from the 24V wiring.

Yes, 24V control works with any heat pump thermostat. Always connect the L terminal (the refrigerant leakage shutdown signal). W2/Aux accepts a second-stage call for electric heat, and DH accepts a dehumidification signal.

The air handler has five static-pressure blower settings; Speed 3 is the default. Set the speed per the blower charts regardless of whether RS485 or 24V control is used, matching the outdoor unit capacity and the duct design. Only the HEAT (SA2) dip switches are adjusted for fan setup, with power off.

In Strong Mode the compressor increases speed at a higher rate than Standard to reduce ramp-up time, but it is less efficient. In Energy Saving Mode the compressor ramps more slowly, which can increase efficiency and provide additional dehumidification; the guide's example is replacing a system a half ton smaller than the FLEXX Ultra R32 being installed. Strong Mode and Energy Saving Mode cannot be enabled at the same time. Operating modes are set with dip switches SA1 #3 and #4; Standard is the default.

Use Strong Defrost Mode in cold but high-humidity environments, such as areas near large bodies of water, or where it is common practice to extend defrost timing or increase defrost frequency. In other cases where Standard Defrost seems insufficient, first make sure the system is in good working order, the outdoor coil is clean, and the charge is correct before changing the setting. Defrost is set with dip switches SA2 #1 and #2; Standard is the factory default.

Per the guide, an E6 results when the unit is on its default RS485 communication setting and the H1/H2 terminals are not connected at the indoor and outdoor unit. Either connect H1/H2 at both units or set the SA1 #1 dip switch to 24V control at both units.