Errors of Aux air conditioners: how to identify a malfunction and restore the split system

Alexey Dedyulin
Checked by a specialist: Alexey Dedyulin
Author: Olga Kiseleva
Last update: January 2020

Isn't it, it would be great if a split system breaks down, not looking for a repairman or going to a service center. It would be nice to figure out what the cause of the malfunction is.

Standard errors of the AUX air conditioner can be eliminated with your own hands, as most of them are associated with mechanical damage to device parts, malfunctions and wear of equipment.

In order to determine the cause of the failure as accurately as possible, you need to familiarize yourself with the basic error codes and signs of typical malfunctions of HVAC equipment in advance. We will talk about how to identify a violation and restore the performance of the equipment. Our tips will be useful to home craftsmen.

Features of AUX brand air conditioners

Aux split systems, which consumers usually encounter, are semi-industrial and household models. Industrial air conditioners are installed mainly in large industrial enterprises.

In the domestic and semi-industrial segment of HVAC equipment, the most diverse type and technology of equipment is presented. The company produces ordinary and inverter installations. The assortment includes wall and cassette split systems, mobile floor models, etc.

Wall systems are usually installed in private homes and apartments, and cassette air conditioners are mounted in office, commercial and industrial premises. The quality of AUX air conditioners is highly dependent on OEM suppliers. It is better to take equipment Aux in specialized firms. Such companies are more likely to buy high-quality equipment.

Aux air conditioners are presented in several series: FJ, Legend Standart (LS), LS Inverter, Legend Design Inverter and Legend Exlusive Inverter. They are designed for different areas of refrigerated spaces. In addition to models with a basic set of functions, there are modernized versions.

AUX air conditioners for sale
All AUX brand air conditioners have an attractive design, multifunctionality and low price, and therefore are popular in the market

Split systems of all AUX series are designed for cooling, heating, drainage and ventilation of the room. The cooling function can work at temperatures from +15 to +43 degrees, and the heating function is above 0.

You cannot run a split system at lower temperatures without additional technical training. The operation of climatic equipment at low temperatures can lead to its breakdown. Also, air conditioning in heating mode is not considered an alternative to heating.

Checking the room temperature
Before starting the air conditioner, you need to check the air temperature in the room and only then turn on this device in the network

There are many varieties of split systems Aux. In terms of functionality, models of air conditioners with similar abbreviations differ little from each other. Their main differences are in appearance, additional features and power.

AUX brand air conditioner breakdown

AUX conditioners are reliable enough, but they periodically break down. Before repairing the device, it must first be fully diagnosed.

During the diagnosis, the condition of all parts of the split system is checked:

  • fastenings of internal and upper blocks;
  • clamps of all contact connections;
  • air filters;
  • weekend blinds;
  • drainage system etc.

During diagnosis, the AUX air conditioner starts in test mode. The test mode is similar to the standard mode, but during it the equipment does not respond to the room temperature and sensor readings. During the diagnosis, key parameters of the split system are recorded and errors are detected.

Self-service air conditioner
To check the main technical indicators of the air conditioner and search for possible malfunctions, you need to run it in test mode

Many errors of household air conditioners can be fixed independently. Conventionally, all breakdowns of air conditioners can be divided into malfunctions of the refrigeration circuit and malfunctions of the electronics (failure of the electrical elements of the system).

Most often, fans break in Aux split systems, compressors, board or outdoor unit heat exchanger. The fact is that the main load during the operation of the device is precisely on them, so these parts quickly wear out.

If the fan breaks down, the system usually turns on for a few seconds, and then turns off again. This may indicate a malfunction of the blades, motor, and capacitor of the fan motor. The nature of the breakdown is determined by checking the winding resistance tester.

Testers for the electrical part of the air conditioner
To accurately check the resistance and winding, the problematic place of the device must first be called with a multimeter, and then take a megaohmmeter

For any of these faults, replace the part. Fan repair takes no more than an hour or two. You can do it yourself or contact a service center.

In the event of a compressor failure, the air conditioner does not turn on at all or turns on for several minutes. Sometimes, when the device is turned on, a strong humming sound is issued. Also, with this malfunction, a frequent change of stop and start cycles occurs.

This can happen due to improper phase switching, condenser breakdowns, failure of the expansion valve and the compressor crankcase being filled with liquid freon. In most cases, you can limit yourself to repairing the compressor; you do not need to completely change the part.

Air conditioning compressor
A compressor is a part of an air conditioner, which is necessary to compress freon and ensure its free circulation along the working circuit

Phase imbalance problems usually indicate an improper load distribution in the network. Checking the phase connection is carried out by clamp meters. If problems are detected as a result of this measurement, the load is redistributed.

If the crankcase is filled with liquid refrigerant, it is necessary to bleed freon, evacuate the system and charge the circuit. You should also reconfigure the operation of the pressure capacitor regulator.

Problems in the electronic part of the air conditioning equipment are considered the most serious. A failure in the hardware software is corrected by reprogramming the system, which is best done in a service center.

The control board may burn out during power surges or in the event of a short circuit. In this case, the broken microcircuits are soldered and soldered in their place by new ones, checking in parallel the buffer microcircuit.

Sometimes the cause of a malfunction in the control board is an interconnect error when installing equipment. In this case, diode bridges, a voltage regulator or a transformer burn out. If the board burns out completely, it must be replaced with a new one. Replacing a burned-out control board is done in several stages.

Checking and repairing the air conditioner
The simultaneous flashing of all lamps in the split system indicators is usually associated with a malfunction of the software settings of the control circuit board caused by the non-compliance of the network parameters with GOST standards

First, the device’s power is turned off, after which the case is disassembled or the top cover of the unit is removed. Then the board is pulled out from the grooves (all fixing screws are loosened in parallel). After that, a new board is installed, and the unit is assembled in the reverse order.

But before any diagnosis and repair of HVAC equipment, you need to make sure that it is correctly selected and well installed.

If the power consumption of the air conditioner is not designed for a large room, and the split system was installed there, then the device will not be able to create the desired temperature regime, and therefore it will periodically generate errors. After all, the air conditioner will constantly be in operation and heat up, as a result it will break quickly enough.

Air conditioner power calculation
When choosing an air conditioner for an apartment or a house, you need to adhere to the basic recommendations on the ratio of the area of ​​the refrigerated space and the power of the split system

In the case of illiterate installation of the split system and violation of the basic technical requirements during its installation, it will work incorrectly.

For example, with insufficient slope of the drainage tube, the water that has fallen out during condensation cannot be completely removed from the device. This can lead to breakdowns, and if there is too much difference in height between the indoor and outdoor air conditioning units, the compressor will pump the freon with insufficient pressure.

Typical symptoms of a split system malfunction

If the Aux split system breaks down, first it need to be cleaned. The cause of the breakdown of the device may be normal pollution, so you need to immediately eliminate it. A layer of dust on the device reduces its efficiency by about 2-2.5 times.

Dirty air conditioner heat exchanger
A dirty air conditioner not only looks awful, it also does not fulfill its basic cooling and heating functions. If there is too much dirt, the split system simply stops cooling the air in the room to the desired temperature values

If the air conditioner does not work after cleaning, you need to look at the remaining signs for troubleshooting.

These signs include:

  1. The operation of the indoor unit without cooling. In this case, the blinds of the indoor unit open, the fan spins, but the air temperature in the room remains unchanged.
  2. Leaking water from the indoor unit.
  3. The lack of reaction of the air conditioner to pressing the keys on the remote control.
  4. Sudden shutdown of the split system after prolonged use.
  5. Problems with the compressor and fans.

But if the air conditioner does not work, you first need to make sure that it is securely connected to the mains. In addition, you need to check the status circuit breaker and fuse on the supply line.You should also make sure that all device modes are turned on correctly.

Air conditioning works but does not cool

If the cooling function does not work in the AUX split system, you must first check its settings and operating conditions, as well as the operation of the compressor. If the compressor does not work, then it will not work to repair the device without knowledge and experience in this area.

In this case, the cause of the breakdown may be:

  • malfunctioning temperature sensors;
  • problems with the starting capacitor of the compressor;
  • combustion of compressor power contacts;
  • compressor failure;
  • breakdown of the control board.

If the compressor is running, the air conditioner should hum and vibrate slightly. In this case, the problem is a lack of freon (refrigerant). The refrigerant level is diagnosed using pressure gauges (they measure the pressure in the system).

In most cases, freon leakage occurs at the connections of copper pipes along air conditioning tracklaid between indoor and outdoor units. At the point of leakage, oil remains, on which dust adheres.

The formation of an optimal microclimate
Freon is a saturated aliphatic fluorinated hydrocarbons that are absolutely safe for humans and pets and used in the air conditioner for cooling.

A small refrigerant leak (up to 200 g per year) is considered normal and natural. It occurs due to the mechanical connection of the main pipes and due to errors during installation. This problem is solved by refueling the refrigerant during the annual service.

To prevent the refrigerant from evaporating too much, we recommend that you clean the equipment in a timely manner. It is necessary to undergo service maintenance and periodically refuel the split system.

If this is not done, the system will have low pressure due to a lack of freon. And because of the low pressure in the line, freezing of the pipes and the heat exchanger can occur, which will ultimately lead to compressor failure.

Strong leak and its consequences are usually eliminated by soldering. The burner heats the freon leak on the pipe and solders it. In addition, leaky tubes can be completely replaced by soldering them with nitrogen.

Refrigerant leaks can be detected by measuring pressure on the suction line. A reduction in suction pressure below zero must not be allowed. In this case, air will enter the system along with moisture, which can cause internal corrosion of the compressor.

UV lamp for air treatment
Often, electronic leak detectors and chemical leak indicators with special ultraviolet lamps are used to search for refrigerant leaks in air conditioners.

In addition, the insufficient development of the power of the air conditioner can be associated with a weak voltage in the mains. In this case, the split system will not work correctly. If this malfunction is detected, the climate control equipment must be switched on through the stabilizer.

Leaking water from the air conditioner

Leaking water from a split system is most often associated with clogging of a drainage hose or tray. To eliminate this problem, it is necessary to disassemble the indoor unit and clean the drainage system. Also, such smudges may be associated with defects in the condensing liquid collection system.

Air conditioning drainage system
The air conditioning drainage system needs to be checked and cleaned regularly, as it is a place with high humidity, ideal for propagating microorganisms

Those. usually water flows from the unit due to imperfect construction. To find the exact cause of the malfunction, you need to disassemble the indoor unit. Then you need to start the air conditioner and in the process of its work to determine the breakdown.

Sudden air conditioner shutdown

If the air conditioner works for a long time and then suddenly turns off, this may indicate overheating of the compressor, clogging of the capillary tube, inoperative fans and a malfunction of the electronics. Electronics failure is the most complex violation, which requires the participation of the master in fixing the problem.

Split system repair
Electronics breakdowns in an air conditioner usually occur due to power outages that result in any part of the device burning out.

The search for electronics problems should begin with vulnerable parts: fuses and transformers. If burnt parts are found, you need to find the cause of the breakdown and eliminate it. If the fuses and transformers are in order, you need to check the status of the board: capacitors, relays, voltage stabilizers, diode bridge, etc. But the board is usually not repaired, but replaced with a new one.

Error codes of the AUX split system

All Aux air conditioners have a self-diagnosis system that, when a malfunction is detected, displays error codes on the equipment. This is a clue where to look for the cause of the problem. The failure coding in work consists of numbers and Latin letters. Error indications on different models of climate technology may vary slightly.

Unified teams include:

  1. Type of failure Display of digital pipe (without alphanumeric designation) - display unit malfunction.
  2. E1 - malfunction of the temperature sensor (thermistor) of the indoor unit. In parallel with this indicator, the yellow timer LED (once every 8 seconds) flashes on the indoor unit. The system at this moment is completely stopped and does not respond to external commands.
  3. E2 and E3 - errors of evaporator sensors.
  4. E4 - malfunctions of the fan motor (PG feedback motor).
  5. E5 - errors of the outdoor unit of the air conditioning equipment (Outdoor protection function).
  6. E6 - errors of the fan motor of the indoor unit of the split system.

In this case, the exact nature of the error depends on at what exact moment the functioning of the air conditioner displayed one or another indicator on the device.

Error E3 most often appears after 5-10 minutes of operation of the split system. This may be due to:

  • problems with power contacts;
  • severe contamination of the filter or evaporator (because of this, the fan accelerates extremely quickly without load;
  • problems with the RPM sensor, etc.

Upon occurrence E4 errors air conditioning, as a rule, does not work in ventilation and cooling modes. But when you turn on the device in heating mode, it immediately gives an error. The problem indicates a malfunction of the fan of the indoor unit of the Aux brand air conditioner.

Split fan
The fan of the indoor unit is an important part of the air conditioner, which provides forced air circulation through the heat exchanger due to the fact that it blows the cold formed on the radiator into the room

When diagnosing the air conditioner, you need to consider the time at which an error is issued. If the code is displayed on the switched off device, this may indicate problems with the controller, and not with the part itself.

Those. the controller just hangs and periodically gives an error code. If after checking all the elements of the split system it becomes clear that they are serviceable, you need to check the control board and, in case of failure, replace it.

Failures of individual models

In addition to typical indicators, there are many error codes that are specific to a particular model of air conditioner. AUX split-systems of models ALHi, ALCa and ALCe have an additional decoding of the error codes that appear.

E6 code can have different meanings depending on the types of split systems. For three-phase outdoor units of air conditioners with an index of 36 and higher (an exception is only model 36A4), this indicator indicates a rephasing or undervoltage in the system.

For outdoor units of split systems with a pressure sensor with an index of 30 or higher, this error code indicates a low pressure in the system.

Air conditioner pressure measurement
Low pressure in the air conditioner negatively affects the functioning of all its parts, especially the evaporator and condenser are affected

In blocks of cassette type, an error code E4 indicates an accident in the drainage of the air conditioner. In addition to this indicator, a yellow timer LED flashes on the device case.The E2 indicator indicates that the copper temperature sensor is open and there is no signal.

In case of some malfunctions of the Aux air conditioner, no signals are displayed on the panel, and only indirect signs indicate breakdowns. If the split system continues to work, but the yellow timer LED flashes on the case (2 times), this indicates a problem with the temperature sensor on the condenser.

If the timer LED flashes green on a working air conditioner and no identifiers are displayed on the display, this indicates that the defrost mode of the outdoor unit has started. Also on AUX air conditioners, a blinking timer LED 4 times every 8 seconds indicates a malfunction in the power supply.

If any malfunction is detected, disconnect the device from the power supply to prevent accidental malfunctions. If you turn on the device half an hour after turning it off and the air conditioner does not recover, it is recommended to contact the Aux service center.

Conclusions and useful video on the topic

The error codes of the Aux air conditioner allow you to determine the nature of the malfunction, but before deciphering them, it is better to familiarize yourself with the typical breakdowns of the split systems of this brand and methods for eliminating them in advance.

The video below talks about the most common problem with air conditioners - freon leakage:

Having determined the value of the indication, the owner of the climate technology is able to decide on a further action plan. Everything must be carried out in accordance with the operating instructions and safety regulations. For example, he can fix a small problem himself, and in case of a more serious breakdown, contact a service center.

Please write comments in the form below the block. Tell us about how you found a malfunction in the air conditioner yourself. Ask questions on the topic of the article, post a photo with the repair process or search for errors.

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