Why does the air conditioner not cool the room, but blows warm air?

What determines the cooling capacity of an air conditioner?

Cooling capacity is the main characteristic of an air conditioner, which determines the efficiency of the climate control equipment. The cooling power parameter is selected taking into account the area of the room where the device will be installed. For the calculation, the following formula is taken: per 10 sq. m of room with ceilings no more than 3 meters - 1 kW of cooling power.

Now let's look at how to determine whether the cooling of the air conditioner has really deteriorated and whether there is a need for repair work, or whether such an assessment of the performance of the device turned out to be biased.

The cooling capacity of climate control systems largely depends on the outside air temperature. An efficiently operating air conditioner will provide optimal air temperature indoors, the difference of which can be 8-120 or more. If the difference in temperature outside and in the room where the air conditioner is operating is less than this parameter, then we can conclude that the split equipment is faulty.

Cleanliness is the key to warmth

It happens that the air conditioner heats well, but the airflow is poor. A possible reason is clogged filters. They are located under the front panel. Open it by pulling the two tabs on the edges and check their condition. If necessary, remove and wash them with dishwashing detergent.

If the air conditioner blows well, but the temperature is insufficient, the evaporator radiator may be clogged. It is located in the indoor unit of the air conditioner. This problem often occurs with appliances installed in kitchens.

It's easy to check its condition - open the front panel by pulling the two latches on the edges. Then remove the filters - underneath there is a radiator. If it is dirty, clean it with a brush. If there is greasy or hard deposits on the grill, use dishwashing liquid. Read more about cleaning in the article “How to clean an air conditioner at home yourself - step-by-step instructions.”

Why did the air conditioner not cool well?

Air conditioners lose the ability to quickly and efficiently cool the air for various reasons, which cannot always be determined without the help of a specialist. Let's look at the most common causes of this malfunction.

Why the air conditioner does not cool the air:

the filters or the fan of the indoor unit are dirty;
the heat exchanger in the indoor or outdoor module is dirty;
capillary tube clogged;
there is not enough freon in the system;
refrigerant leak;
fan malfunction;
breakdown of the 4-code valve in the external unit of the split system;
compressor malfunction;
temperature sensors are faulty;
breakdown of pressure sensors.

The main breakdowns of air conditioners and their causes

Main faults causing cooling problem

The problem with cooling is accompanied by leakage and freezing of the internal unit of the split system (the unit installed on the side of the room). Most likely, the reason lies in clogged cleaning filters: if dirt accumulates in them, it settles on other elements of the device (on the heat exchanger plates, on the evaporator, on the fan), which ultimately leads to a deterioration in the heat transfer of the radiator and a decrease in cooling capacity. Solution: the filters must be removed and cleaned, as well as clean other elements of the indoor unit if dirt has accumulated on them. Filters are relatively easy to clean, but disassembling the indoor unit to clean and put it back together is best left to professionals.
The problem is accompanied by overheating and shutdown of the compressor (a device in the external unit of the split system). The cause of malfunctions is contamination of the radiator; it is the dirt that makes it difficult for the fan to rotate, causes the compressor to overheat and reduces the cooling efficiency. Solution: cleaning the outdoor unit. If the air conditioner is installed on one of the upper floors of a high-rise building, you cannot do without the services of industrial climbers.
The intensity of the air flow from the air conditioner has not decreased, but the device cools the air poorly. The problem is a lack of freon (a type of refrigerant - a working substance, without which the process of changing temperature is impossible). A deficiency can be caused by leakage or evaporation (over the course of a year, 7% of the refrigerant will evaporate from a fully sealed and properly functioning unit). Solution: refilling the air conditioner with freon will make up for the lack of working substance.
The compressor began to work in enhanced mode, but at some point the electric motor overheated and turned off. There is still a strong air flow from the device, but the air conditioner does not cool. If the device is equipped with a warning system, the error message “Low pressure” appears. All these consequences occur due to a sharp decrease in the amount of freon, i.e. refrigerant leaks. Solution: to eliminate a leak, the services of specialists are required; they will find the location of the leak, take action, and after that, fill the air conditioner with freon.
The compressor also turns off due to overheating, the air conditioner blows without cooling. But the problem lies not in the pressure, but in the breakdown of the fan in the outdoor unit. The fan may fail due to overheating of the motor (if dust gets on the motor). Solution: the fan and its electric motor need to be replaced.
The air conditioner blows as usual, the compressor in the outdoor unit runs constantly without turning off, but the air in the room does not cool. The problem is accompanied by freezing of elements in the internal block of the split system. Such consequences occur due to clogging of the capillary tube, which is designed to equalize the pressure in the event of a compressor shutdown. The blockage leads to a deterioration in the circulation of the working substance and to the appearance of ice on the evaporator, the tube leading from it and other components of the external unit. Under such conditions, effective air cooling is impossible, even with continuous operation of the air conditioner. Solution: the blockage can be removed using a hydraulic press, sometimes, if the blockage is severe, using proven solvents (do not use those that can damage the engine). Sometimes the capillary tube is replaced with a new one (but only in extreme cases, since the “native” one performs its role more effectively).
During cooling mode, hot air comes out of the air conditioner. A four-way switching valve is responsible for changing modes. If it is faulty, the technician will repair or replace the valve with a new one.
The split system blows out warm air instead of cold air. There are three reasons for this: the connections between the indoor and outdoor units are damaged, the circulation of freon is disrupted, as a result, the air conditioner acts as a regular fan - it is necessary to restore the power supply, eliminate wiring problems,
the control board is faulty due to burnt out elements - you need to check which elements are burnt out (power relays, microcircuits, microprocessor) and either fix the problem by cleaning the contacts or replace the control module,
failure of the inverter module in the outdoor unit, due to which the current to the compressor stops flowing - the module needs to be replaced.

Warm air comes out of the air conditioner, and the room temperature remains at room temperature. And the compressor does not work. There may be three reasons:

short circuit in the compressor winding - you will have to replace the compressor with a new one or even the entire outdoor unit,

the capacitor of the external unit is broken - the component is dismantled and replaced with a new one,

The compressor relay, which is responsible for protecting the electric motor from overheating, is faulty - the relay needs to be replaced.

The problem is accompanied by the air conditioner turning off (it turns on and turns off immediately). One of two malfunctions leads to such consequences:

failure of the sensor in the indoor unit that monitors the temperature in the room (thermistor) - the air conditioner turns off due to the fact that the thermistor sends an incorrect signal to the control unit (replacement with a working sensor is necessary),

failure of the sensor that monitors the temperature of the components that are responsible for the pressure in the system - the sensor must also be replaced.

What problems can you solve on your own?

Some air conditioner malfunctions that cause poor air cooling can be eliminated yourself.

What problems can be solved without the help of a specialist:

Dirty filters can be cleaned. To remove them, you need to open the lid of the indoor unit, remove the filters and rinse them under cold running water. After a little drying, the filters are installed in place. Now you can start the air conditioner and check its performance.
A dirty heat exchanger can be cleaned in different ways: with a steam cleaner, a high-pressure washer or special chemicals. If difficulties arise, call service.
The owner can also clean the dirty indoor unit fan himself using a brush or high-pressure washer.
If the cause of the malfunction is a clogged capillary tube, it must be cleaned by blowing or pressing. If the tube is clogged with moisture, cleaning is carried out using a vacuum method.

Problems you can fix yourself

When trying to figure out why your air conditioner isn't cooling, the first thing to do is look at the settings. Maybe the temperature is set too high and you just need to set it to a lower value. If the modes are selected correctly, but the cooling is still ineffective, it is worth continuing to look for the problem.

If the air conditioner does not cool the air, the reasons are as follows:

Symptom of malfunction	Probable Cause	What to do
The device turns on, but does not cool.	Ventilation mode selected.	Set cooling mode.
There is airflow, but it is not cold enough. The indoor unit is leaking and there is icing.	The air filters are very dirty, which is why the radiator does not release cold. If the contamination is severe, the evaporator tubes may become covered with ice. The unit may leak due to a clogged drain pipe.	Clean the filters. They are easy to take out and wash in warm water (not hot!). You need to rinse the pan and drainage tube and treat them with an antiseptic.
The split system blows a barely cold air stream, the compressor of the external unit turns off after a while.	The radiator of the outdoor unit is dirty. If there are flowering plants near the house, they quickly clog the heat exchanger with fluff. This significantly impairs heat transfer, and the compressor turns off due to overheating.	Clean the radiator with a high pressure washer. Doing this yourself is only possible in a private house or if the block is hanging on the ground floor. In other cases, specialists with an aerial platform will be required.
Warm air comes out of the blinds. The outdoor unit's compressor turns on for a few seconds or minutes and then turns off.	It may be due to low mains voltage.	You need to install a voltage control relay.

If you have examined everything and have not found a breakdown, you will need the help of specialists.

Reasons why your air conditioner is not cooling the air in your room that require professional help

Symptom of malfunction	Probable Cause	What to do
After downtime or prolonged use, the system began to cool worse.	Lack of freon. Even a completely sealed system leaks some refrigerant, and the losses must be replaced.	Refuel.
There is airflow, but no cooling. After some time, the device stops turning on and displays a message about low pressure.	The air conditioner has a freon leak.	Find the leak and seal it. Then pump in the full volume of freon.
There is very little cooling, but the compressor does not turn off. The tube may be frozen.	The capillary line is clogged. Freon circulates poorly or does not circulate at all.	To remove the blockage, you need to blow out the pipeline or use a solvent.
Hot air blows (on models with heating function) when the cooling function is on.	Damage to the four-way valve, which is stuck in heating mode.	The valve needs to be repaired or replaced with a new one.
The air conditioner has stopped cooling the air in the apartment, there is a warm flow from the blinds, the compressor turns on for a couple of seconds and then turns off.	The compressor of the outdoor unit has broken down.	In rare cases, the compressor can be repaired. It is more advisable to install a new compressor or even another outdoor unit.
	Failure of the starting and/or running capacitor.	The capacitor needs to be replaced.
Doesn't cool well and turns off before reaching the set temperature.	Faulty temperature sensors.	Replace sensors.

If the air conditioner does not cool the air in the apartment, and it was not possible to find the reason, it will detect a problem. We work with all well-known brands of split systems, use professional equipment, and provide a guarantee on all work.

When you can't do without professional help

In all other cases, you cannot do without the help of professional craftsmen. Specialists will conduct diagnostics and determine the exact cause of the breakdown. If necessary, they will refuel with freon. If a refrigerant leak is detected, it is sealed.

A broken compressor, condenser, fan, as well as pressure and temperature sensors must be repaired or completely replaced with new parts. It all depends on the malfunction and the price of the issue.

Don't ignore the problem of poor air conditioning. Minor faults can be easily fixed without requiring large expenditures. But if you ignore the fact of ineffective operation of the device, you can expect serious breakdowns, the repair of which will have to cost a lot of money.

Follow the operating rules and timely perform technical inspections of climate control devices. Experienced specialists from the service center will always help you solve this problem.

Malfunction of system elements

As a result of improper maintenance of split systems, the functionality of:

There is one of the fans, so the air conditioner in the apartment does not cool. It may not work completely or partially. The problem can only be fixed by a qualified technician.
Four way valve. It is located on the outdoor unit and is responsible for switching heat/cold modes. As a result, it requires repair or complete replacement.

Compressor, due to an interturn short circuit, holes in the windings on the housing, or an internal break. The thermal relay may also fail, the replacement of which is inexpensive. But if the compressor itself fails, repairs will not be cheap; you may have to replace the entire external unit.

How to set it up correctly

There is a possibility that you have set the settings on the remote control incorrectly. The three-way valve acts as a switch and allows you to change the operating mode from cooling to heating. This mode is designated on the remote control as HEAT. If the cooling mode is on, and you set the temperature on the remote control to 20 degrees, the device simply will not work.

Sometimes the air conditioner cannot pick up signals from the remote control and you need to turn off the power to the air conditioner or remove the batteries from the remote control for 10 minutes.

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