Gree F4

What does Gree F4 mean?

F4 means the outdoor tube (condenser coil) temperature sensor is open- or short-circuited. In cool, fan or dry mode the indoor fan keeps running while the compressor and outdoor fan stop; in heat all loads stop. The display shows F4.

Symptoms

• Display shows F4
• In cool/fan/dry the indoor fan runs but compressor and outdoor fan stop; in heat all loads stop
• No cooling or heating output
• Fault sets at start-up or shortly into a run

Common causes

• Outdoor tube (condenser) temperature sensor not connected well
• Temperature sensor damaged
• Connection wire short-circuited or broken
• Outdoor main board fault

Diagnostic steps

1. 01

   Reseat the sensor

   Check the terminal between the condenser tube sensor and the control board for looseness or poor contact and insert it firmly.

2. 02

   Check for shorts

   Look for a short caused by tripped-over parts on the board and set them upright.

3. 03

   Test resistance

   Measure the sensor against the resistance table in the manual; replace with the same model if out of spec.

4. 04

   Replace the board

   If sensor and wiring are sound, replace the outdoor controller board with one of the same model.

When to call a professional

The condenser tube sensor and outdoor control box are in the outdoor unit alongside live mains components. Resistance verification and board replacement are technician work. If F4 does not clear after a connector reseat, stop resetting the unit and bring in a licensed HVAC technician.