We will explain error E4 in various air conditioning brands.
Error e4 Air Conditioner:
Let’s begin by stating that error E4 can indicate issues with a temperature sensor in the air conditioning unit. These sensors are primarily NTC-type electrical resistors, with their resistance decreasing as temperature rises. The control board responsible for this regularly provides a voltage, typically around 5 volts, which varies with resistance.
The affected brands and their specific issues are as follows:
- Carrier: Problems may include an open circuit or a short circuit in the ambient temperature sensor, whether it’s located indoors or outdoors, depending on the unit’s model.
- Midea: The problem often involves the outdoor unit’s temperature sensor.
- York: Issues may arise with the indoor ambient temperature sensor, especially in central York air conditioning units, where the temperature sensor in the compressor discharge tube can be problematic.
- Bosch, Westinghouse, Fujitsu: Error E4 typically relates to problems with the indoor ambient temperature sensor, such as an open circuit or a short circuit.
- Trane, Gree, Sharp, Electrolux, Kelvinator: Error E4 serves as a protection mechanism against high compressor exhaust temperatures.
- Haier (indoor unit): Error E4 indicates an incorrect EEPROM. In portable Haier air conditioners, it signifies the unit has a built-in tank that requires periodic emptying.
To assess the temperature sensor, use a multimeter set to the kilohm scale. Disconnect the sensor and measure its resistance, which should decrease when you touch it. The sensor should not display infinite or zero resistance; its value should be cross-referenced with the manufacturer’s catalog.
Additionally, check if the control board supplies the sensor with the correct voltage. With the sensor connected, the multimeter should read approximately 2.5 volts in the DC voltage scale, as depicted in the figure.
In the case of Daikin, error E4 is attributed to the activation of the low-pressure switch (LBS), indicating a detected lack of liquid or gas pressure in the air conditioning system.
For Samsung, error E4 can be linked to forced defrosting, low refrigerant gas levels, a malfunctioning pump, a damaged temperature sensor, or variations in system pressure. Refrigerant leaks result in reduced pressure, detectable using an ammeter clamp since the air conditioner’s electricity consumption decreases in the presence of a refrigerant gas leak. Furthermore, you can visually inspect for oil stains on both the outdoor and indoor units and pipes, as refrigerant leaks leave traces of lubricant.