The main malfunctions of the air conditioner and ways to eliminate them

Any air conditioner is a complex electronic device that consists of many interconnected parts. Modern refrigeration machines are created using the latest technologies, but this does not prevent the failure of one or another important component, which makes further work impossible.

Timely service and repair of air conditioners helps to eliminate many malfunctions before the device finally fails. As a rule, the owner of such equipment must from time to time order professional cleaning and diagnostics of the system, after which the climatic technician informs the user about all possible and existing problems.

Air conditioner repair can be carried out both on site and in service conditions. It all depends on the complexity of the breakdown, as well as on the owner's willingness to pay for the dismantling and subsequent installation of equipment.

Broken fan, compressor and air conditioner control board

What are the most common air conditioner malfunctions?

Conventionally, all failures can be divided into malfunctions of components of the refrigeration circuit and malfunctions in electronics or failure of electrical components of the system. Most often, users of the same split systems are faced with breakdowns of the board, fan, compressor, or a leak in the heat exchanger of the outdoor unit. This is due to the fact that the main load is on these parts, therefore, their wear, especially if the operating conditions are not observed, is inevitable.

Fan

What can happen to the air conditioner fan and what repairs are made in certain situations?

Some malfunctions are indicated by error codes displayed on the indicator panel of the indoor unit. If the fan "flew", then most likely the system will turn on for a few seconds, and then turn off again. There are several reasons here:

• faulty fan blades;
• the fan motor is faulty;
• the fan motor capacitor is defective.

In all three cases, the solution to the problem will be to replace the failed part.

The service worker first of all checks the resistance of the windings with a tester, which are different for different models of refrigeration machines and are given in the manuals. If the suspicion is confirmed, then they begin to repair the air conditioner fan.

Replacing the fan impeller:

• Remove the front protective grill;
• Unscrew the fan mounting nut (left-hand thread);
• Remove the impeller from the motor pulley;
• Put a new impeller on the pulley;
• Collect parts in reverse order.

Replacing the fan motor:

• The system is de-energized and the protective front grill is removed;
• Unscrew and remove the fan mounting nut (left-hand thread);
• Disconnect all electrical connections to the fan motor;
• Unscrew the motor itself from the case and remove it;
• Put on a new part;
• Collect and fix the parts in the reverse order.

Replacing the fan motor starting capacitor:

• Completely de-energize the system;
• Disassemble the case of the outdoor unit;
• Unscrew the condenser fixing bracket;
• Disconnect all wires from it;
• Replace with a new starting capacitor;
• Collect and fix the parts in the reverse order.

Usually, the repair of an air conditioner fan takes no more than an hour in time.How much such a repair costs depends on the urgency of the work, their volume, the power of the air conditioner, the amount of materials and spare parts used.

Compressor

What are the main malfunctions of the air conditioner compressor, and what repairs are carried out in this or that case?

Most often, a compressor breakdown is indicated by incorrect operation of the device, namely:

• it does not turn on at all or there is a turn-on delay for several minutes;
• it does not turn on and at the same time emits a corresponding buzz;
• frequent change of start and stop cycles.

The reasons may be incorrect inclusion of phases, malfunction of the starting capacitor, filling the compressor crankcase with liquid freon, failure of the expansion valve or four-way valve. This is not a complete list of problems. But most of them do not require replacement of the compressor itself. It is enough to eliminate the cause and the device functions normally.

If there is a phase imbalance, then most likely the load in the network is distributed incorrectly. An air conditioner with a three-phase connection cannot be installed on a single-phase network and vice versa. They usually check the current on each phase with a clamp meter and redistribute the load. An electrical panel bulkhead may be required.

If liquid refrigerant fills the crankcase, then it is necessary first of all to bleed the existing freon, evacuate the system, and then refuel the circuit, since it is the lack of refrigerant that causes such problems. It may be necessary to reconfigure the operation of the condensing pressure regulator.

If the problem is in the operation of the four-way valve, then it is worth remembering that replacing it will not cost much less than repairing an air conditioner compressor, therefore, first, check the health of the electrical circuit and whether there is enough freon in the circuit. When the problem persists (blowing warm air in any mode), then this part can be evaporated, but this is done only if there is no need for subsequent heating.

You may need to replace the oil with a better one or try to apply power for a short time to the four-way valve. As a last resort, replace it.

When a complete replacement of the compressor is required, they do it in the following sequence:

1. Collect freon from the system with a manometric station.
2. De-energize the device.
3. Dismantle the outdoor unit.
4. Disassemble its body.
5. Disconnect the tubing and electrical wires from the compressor.
6. Remove the compressor from the vibration dampers.
7. Install a new one on vibration dampers.
8. Fix and solder all the tubes back.
9. Connect the wires.
10. Assemble the body and mount the block back.
11. Connect tubes and wires.
12. The circuit is evacuated and refilled.
13. Include a device for testing.

When repairing an air conditioner compressor, the pipes are brazed using nitrogen.

Electronic control board

How does the control board malfunction manifest itself and in what ways is it eliminated?

If all the LEDs on the indoor unit are blinking, and the split system does not turn on at the same time, then most likely there was a failure in the software settings of the control board. This is eliminated by reprogramming it in the service center using codes, information about which is available only to the employees of this center.

The control board could burn out during voltage surges (inverter systems are sensitive to this) or during a short circuit, so in this case it will need to be repaired - the broken microcircuits are soldered and new ones are soldered, the triacs are replaced with more powerful ones, the buffer microcircuit is checked.

Manufacturers equip control boards with solid-state switches, which are responsible for the rotation of the fan, therefore, malfunctions in its operation may indicate a malfunction of this element. Before proceeding with the repair, it is necessary to measure the resistance of the part. If it is closer to zero, then the broken microcircuit is soldered.

Malfunctions of the compressor, temperature sensors and motion sensors can also be signs of a malfunctioning control board.

When the burned-out microcircuit is visible with the naked eye, there is no need to take resistance measurements. Here, they immediately begin to repair the air conditioner control board - replacing the triac.

Sometimes, during installation, installers make mistakes in interconnect connections, which also leads to a failure or burnout of the board. Most often, diode bridges, a transformer or a voltage stabilizer burn out first. In such cases, it is more expedient to replace the failed part. It is impossible to repair the air conditioner board, if it is completely burnt out, then it is replaced.

Replacing the control board:

• Turn off the power;
• Disassemble the case or remove the top cover of the unit;
• Pull the board out of the slots by unscrewing the fixing screws and disconnecting all the wires and connectors;
• Replace with a new one and assemble the block in reverse order.

It is better to contact the service center immediately, since repairing the board at the air conditioning system is an expensive process, and if you handle the device elements carelessly, additional waste may arise.

Malfunction of the heat exchanger of the outdoor unit of the air conditioner

Split systems have another problem - the leakage of freon through the heat exchanger of the outdoor unit. For cars filled with R-22 freon, they are looking for it using a leak detector; the units running on modern R-410a wash and watch where foaming will take place.

There are two ways to eliminate leakage through the heat exchanger of the outdoor unit:

1. Soldering... The burner heats up the leak on the radiator tube and solder it. This is done very carefully, since the tubes are very thin and melt easily.
2. Substitution... Disconnect the external unit and disassemble its case. Cut out with a pipe cutter or solder the old heat exchanger and replace it with a new one, soldered with nitrogen. Assemble the module back, connect electrical connections, tubes and evacuate the system. Refuel and start up to check the functionality.

When replacing the condenser heat exchanger, the repair of air conditioning systems can take place on site and without additional dismantling work.

What determines the cost of repairing an air conditioner and an approximate estimate

How much does an air conditioner repair cost and what does the pricing depend on?

Several factors are at play here:

1. Difficulty of work... It is much easier, for example, to repair a fan impeller than a compressor.
2. Normal access to the device.
3. Cost of consumables and spare parts... If the master has to change the heat exchanger, and not solder it, then the service rendered will rise in price.
4. Urgency... If you do not want to wait for the specialist to be free, you can order an urgent repair of the air conditioner, but this doubles the cost.
5. Calling at night... Some objects cannot be repaired during the daytime, and the night rate, as a rule, has different rates.

To determine the final cost of repairing the air conditioning system, the master makes an estimate indicating the services provided and the amount of materials consumed. There may be indicated additional services that were provided during the repair.

For clarity, an approximate estimate of the repair of the air conditioner is given below.

Total: 4 thousand 800 rubles 00 kopecks.

All prices in the estimate for the repair and maintenance of the air conditioner are conditional. They can vary significantly from company to company.

Recommended reading

For a deeper study of the issue, it is recommended that you familiarize yourself with the books on repairing air conditioners by the following authors:

1. Bogoslovsky V.N. 1985. Air conditioning and refrigeration.
2. Burtsev S.I., Blinov A.V. 2005. Installation, operation and service of ventilation and air conditioning systems.
3. L. Korkh 2004. Conditioners.
4. Collective authorship. 2010. Training book for the repair of modern air conditioners.
5. A.P. Kashkarov2011. Installation, repair and maintenance of air conditioners.